U.S. patent application number 16/105211 was filed with the patent office on 2019-02-21 for aluminum alloy products having selectively recrystallized microstructure and methods of making.
This patent application is currently assigned to Novelis Inc.. The applicant listed for this patent is Novelis Inc.. Invention is credited to Duane E. Bendzinski, Rajeev G. Kamat, Rahul Vilas Kulkarni, Rashmi Ranjan Mohanty, Samuel Robert Wagstaff, Yi Wang, Cedric Wu, Yudie Yuan.
Application Number | 20190055637 16/105211 |
Document ID | / |
Family ID | 63586887 |
Filed Date | 2019-02-21 |
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United States Patent
Application |
20190055637 |
Kind Code |
A1 |
Wu; Cedric ; et al. |
February 21, 2019 |
ALUMINUM ALLOY PRODUCTS HAVING SELECTIVELY RECRYSTALLIZED
MICROSTRUCTURE AND METHODS OF MAKING
Abstract
The present disclosure generally provides aluminum alloy
products having selectively recrystallized microstructure at one or
more surfaces of the product. The disclosure also provides articles
of manufacture made from such products, and methods of making such
products, such as through casting and rolling. The disclosure also
provides various end uses of such products, such as in automotive,
transportation, electronics, and industrial applications.
Inventors: |
Wu; Cedric; (Marietta,
GA) ; Kamat; Rajeev G.; (Marietta, GA) ; Wang;
Yi; (Los Angeles, CA) ; Wagstaff; Samuel Robert;
(Marietta, GA) ; Mohanty; Rashmi Ranjan; (Roswell,
GA) ; Kulkarni; Rahul Vilas; (Marietta, GA) ;
Bendzinski; Duane E.; (Woodstock, GA) ; Yuan;
Yudie; (Roswell, GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Novelis Inc. |
Atlanta |
GA |
US |
|
|
Assignee: |
Novelis Inc.
Atlanta
GA
|
Family ID: |
63586887 |
Appl. No.: |
16/105211 |
Filed: |
August 20, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62548013 |
Aug 21, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C22C 21/08 20130101;
C22F 1/053 20130101; C22F 1/05 20130101; C22C 21/10 20130101; C22F
1/047 20130101; B22D 11/003 20130101; C22C 21/06 20130101 |
International
Class: |
C22F 1/053 20060101
C22F001/053; C22C 21/10 20060101 C22C021/10; B22D 11/00 20060101
B22D011/00 |
Claims
1. A method of making an aluminum alloy article, the method
comprising: casting an aluminum alloy to form an aluminum alloy
cast product; homogenizing the aluminum alloy cast product to form
a homogenized aluminum alloy cast product; subjecting the
homogenized aluminum alloy cast product to a first rolling process
to form a first rolled aluminum alloy product having a first
thickness, wherein the first rolling process comprises one or more
hot rolling passes followed by one or more cold rolling passes;
annealing the first rolled aluminum alloy product at a temperature
of not more than 50.degree. C. above a minimum recrystallization
temperature of the aluminum alloy to form a first annealed aluminum
alloy product; and subjecting the first annealed aluminum alloy
product to a second rolling process to form a second rolled
aluminum alloy product having a second thickness.
2. The method of claim 1, wherein the aluminum alloy is a 5xxx
series aluminum alloy, a 6xxx series aluminum alloy, or a 7xxx
series aluminum alloy.
3. The method of claim 1, wherein the first thickness is no more
than 10 mm.
4. The method of claim 1, wherein the annealing is carried out at
the temperature above the minimum recrystallization temperature for
no more than 3.0 hours.
5. The method of claim 1, wherein the annealing is carried out at a
first temperature above the minimum recrystallization temperature
for a first period of time and at a second temperature above the
minimum recrystallization temperature for a second period of time,
wherein the first temperature above the minimum recrystallization
temperature is greater than the second temperature above the
minimum recrystallization temperature.
6. The method of claim 1, wherein the second thickness is no more
than 4.0 mm.
7. The method of claim 1, wherein the second rolled aluminum alloy
product comprises: a first surface portion, wherein the first
surface portion comprises a first rolled surface, and wherein the
first surface portion has a first recrystallization quotient; a
second surface portion opposing the first surface portion, wherein
the second surface portion comprises a second rolled surface, and
wherein the second surface portion has a second recrystallization
quotient; and an intermediate portion positioned between the first
surface portion and the second surface portion, wherein the
intermediate portion has a third recrystallization quotient, and
wherein the third recrystallization quotient is less than at least
one of the first recrystallization quotient or the second
recrystallization quotient.
8. The method of claim 7, wherein the first recrystallization
quotient is between 0.50 and 1.0, wherein the second
recrystallization quotient is between 0.50 and 1.0, or wherein the
third recrystallization quotient is between 0.01 and 0.65.
9. The method of claim 7, wherein the first surface portion extends
from a first surface of the first surface portion to a first depth
less than 40% of a thickness of the second rolled aluminum alloy
product, and wherein the second surface portion extends from a
second surface of the second surface portion to a second depth less
than 40% of the thickness of the second rolled aluminum alloy
product.
10. An aluminum alloy article comprising an aluminum alloy
material, the aluminum alloy material comprising: a first surface
portion, wherein the first surface portion comprises a first rolled
surface, and wherein the first surface portion has a first
recrystallization quotient; a second surface portion opposing the
first surface portion, wherein the second surface portion comprises
a second rolled surface, and wherein the second surface portion has
a second recrystallization quotient; and an intermediate portion
positioned between the first surface portion and the second surface
portion, wherein the intermediate portion has a third
recrystallization quotient, and wherein the third recrystallization
quotient is less than at least one of the first recrystallization
quotient or the second recrystallization quotient.
11. The aluminum alloy article of claim 10, wherein the aluminum
alloy material is a 5xxx series aluminum alloy, a 6xxx series
aluminum alloy, or a 7xxx series aluminum alloy.
12. The aluminum alloy article of claim 10, wherein one or both of
the first rolled surface or the second rolled surface is formed by
a process that comprises cold rolling.
13. The aluminum alloy article of claim 10, wherein the first
surface portion extends from a surface of the first surface portion
to first a depth of no more than 40.0% of a thickness of the
aluminum alloy article.
14. The aluminum alloy article of claim 13, wherein the second
surface portion extends from a surface of the second surface
portion to a second depth of no more than 40.0% of the thickness of
the aluminum alloy article.
15. The aluminum alloy article of claim 10, wherein the
intermediate portion extends from a first depth of the first
surface portion to a second depth of the second surface
portion.
16. The aluminum alloy article of claim 10, wherein the first
surface portion has a first recrystallization quotient, wherein the
second surface portion has a second recrystallization quotient,
wherein the intermediate portion has a third recrystallization
quotient, and wherein the third recrystallization quotient is less
than at least one of the first recrystallization quotient or the
second recrystallization quotient, wherein a recrystallization
quotient corresponds to a percentage or fractional amount, volume,
or mass of a portion of the aluminum alloy material that is
recrystallized as compared to a total amount, volume, or mass of
the portion of the aluminum alloy material.
17. The aluminum alloy article of claim 16, wherein the first
recrystallization quotient is at least 0.50, wherein the second
recrystallization quotient is at least 0.50, or wherein the third
recrystallization quotient is no more than 0.65.
18. The aluminum alloy article of claim 10, having a .beta. angle
of between 100.degree. and 138.degree. for bendability testing
according to Specification VDA 238-100.
19. The aluminum alloy article of claim 10, having an exfoliation
corrosion rating of EA for exfoliation corrosion testing according
to ASTM Test No. G34-01.
20. The aluminum alloy article of claim 10, wherein the first
surface portion extends from a first surface of the first surface
portion to a first depth less than 40% of a thickness of the
aluminum alloy article, and wherein the second surface portion
extends from a second surface of the second surface portion to a
second depth less than 40% of the thickness of the aluminum alloy
article.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and priority to U.S.
Provisional Application No. 62/548,013, filed on Aug. 21, 2017,
which is hereby incorporated by reference in its entirety.
FIELD
[0002] The present disclosure generally provides aluminum alloy
products having a selectively recrystallized microstructure at the
surface of the product. The disclosure also provides articles of
manufacture made from aluminum alloy products, and methods of
making aluminum alloy products, such as through casting and
rolling. The disclosure also provides various end uses of such
products, such as in automotive, transportation, electronics, and
industrial applications.
BACKGROUND
[0003] Aluminum alloy products are desirable for use in a number of
different applications, especially those where light weight,
strength, and durability are desirable. For example, aluminum
alloys are increasingly replacing steel as a structural component
of automobiles and other transportation equipment. Because aluminum
alloys are generally about 2.8 times less dense than steel, the use
of such materials reduces the weight of the equipment and allows
for substantial improvements in energy efficiency. Even so, the use
of aluminum alloy products can pose certain challenges.
[0004] One particular challenge relates to the tendency of aluminum
alloy products to undergo recrystallization during and following
certain processing steps. In metallurgy, recrystallization refers
to the process by which deformed grains (e.g., formed as the result
of rolling or other mechanical shaping activities) reorient and
convert into defect-free grains that nucleate and gradually replace
the deformed grains. Recrystallization generally improves the
ductility of the material, but generally does so at the expense of
strength and hardness. Thus, in applications where strength and
hardness are important, such as in certain applications where
aluminum alloys may be used to replace steel, recrystallization can
limit the use of certain aluminum alloys as steel replacements.
SUMMARY
[0005] The covered embodiments of this disclosure are defined by
the claims, not this summary. This summary provides a high-level
overview of various aspects of the invention and introduces some of
the concepts that are further described in the Detailed Description
section below. This summary is not intended to identify key or
essential features of the claimed subject matter, nor is it
intended to be used in isolation to determine the scope of the
claimed subject matter. The subject matter should be understood by
reference to appropriate portions of the entire specification, any
or all drawings, and each claim.
[0006] The present disclosure provides novel aluminum alloy
articles that have surface portions with a higher degree of
recrystallization or recrystallization quotient than portions in
the interior of the article, where a higher portion of the aluminum
alloy material has a recovered and/or unrecrystallized
microstructure. Even though the aluminum alloy articles of the
present disclosure are made from a monolithic aluminum alloy
material, they possess certain benefits of cladded aluminum alloy
materials, such as strength in the core of the article and
ductility in the clad of the article. The present disclosure also
provides methods of making such aluminum alloy articles and
articles of manufacture formed from such aluminum alloy articles.
In some examples, the aluminum alloy article is a rolled article,
such as an aluminum alloy sheet, where the material near the
surface of the sheet has a recrystallized microstructure and the
material in the interior of the sheet has a recovered and/or
unrecrystallized microstructure. The resulting article exhibits the
strength benefits of material in a recovered and/or
unrecrystallized microstructure coupled with desirable bendability
and corrosion properties of material in a recrystallized
microstructure.
[0007] The present disclosure provides an aluminum alloy article,
which is comprised of an aluminum alloy material and further
comprises: (a) a first surface portion; (b) a second surface
portion opposing the first surface portion; and (c) an intermediate
portion between the first surface portion and the second surface
portion; wherein the first surface portion and the second surface
portion comprise a rolled surface; and wherein the aluminum alloy
material of the first surface portion and the second surface
portion have a higher degree of recrystallization or
recrystallization quotient than the aluminum alloy material of the
intermediate portion. In some embodiments, the aluminum alloy
article is an ingot, a strip, a shate, a slab, a billet, or other
aluminum alloy product. In some other embodiments, the aluminum
alloy article is a rolled aluminum alloy article, which is formed
by a process that includes rolling the aluminum alloy article, for
example, until a desired thickness is achieved. In some
embodiments, the rolled aluminum alloy article is an aluminum alloy
sheet, shate, plate, extrusion, casting or forging in any suitable
temper, e.g., an O temper or a temper ranging from the T1 to T9
tempers, and any suitable gauge. In some embodiments, the aluminum
alloy article is made from a 7xxx series alloy as provided
herein.
[0008] The present disclosure also provides a method of making an
aluminum alloy article, the method comprising: providing an
aluminum alloy, wherein the aluminum alloy is provided in a molten
state as a molten aluminum alloy; casting the molten aluminum alloy
to form an aluminum alloy cast product; homogenizing the aluminum
alloy cast product to form a homogenized aluminum alloy cast
product; rolling the homogenized aluminum alloy cast product to
form a first rolled aluminum alloy product having a first
thickness, wherein the rolling comprises one or more hot rolling
passes and one or more cold rolling passes, wherein the one or more
hot rolling passes precede the one or more cold rolling passes;
annealing the first rolled aluminum alloy product at a temperature
of not more than 50.degree. C. above the minimum recrystallization
temperature of the aluminum alloy to form a first annealed aluminum
product; and rolling the first annealed aluminum alloy product to
form a second rolled aluminum product having a second thickness. In
some embodiments thereof, the aluminum alloy articles are subjected
to a final solution heat treatment, for example, the article can be
solution heat treated either through a CASH (continuous annealing
and solution heat treatment) or hot stamping process.
[0009] The disclosure also provides an aluminum alloy article made
by the processes disclosed herein.
[0010] Also disclosed are articles of manufacture comprising the
disclosed aluminum alloy articles. In some embodiments, the article
of manufacture comprises a rolled aluminum alloy article. Examples
of such articles of manufacture include, but are not limited to, a
component of an automobile, truck, trailer, train, railroad car,
airplane, such as a body panel or other part for any of the
foregoing, a bridge, a pipeline, a pipe, a tubing, a boat, a ship,
a storage container, a storage tank, an article of furniture, a
window, a door, a railing, a functional or decorative architectural
piece, a pipe railing, an electrical component, a conduit, a
beverage container, a food container, or a foil. In some
embodiments, the articles of manufacture are automotive or
transportation body parts, including motor vehicle body parts
(e.g., bumpers, side beams, roof beams, cross beams, pillar
reinforcements, inner panels, outer panels, side panels, hood
inners, hood outers, and trunk lid panels). The articles of
manufacture can also include aerospace products and electronic
device housings.
[0011] Additional aspects and embodiments are set forth in the
detailed description, claims, non-limiting examples, and drawings,
which are included herein.
BRIEF DESCRIPTION OF THE FIGURES
[0012] The specification makes reference to the following appended
figures, in which use of like reference numerals in different
figures is intended to illustrate like or analogous components.
[0013] FIG. 1 provides a schematic overview of a process for
preparing aluminum alloy articles.
[0014] FIG. 2 shows an optical micrograph (OM) of Alloy A1, which
is lab rolled and processed, and which shows a recovered and/or
unrecrystallized microstructure through the thickness of the
sample.
[0015] FIG. 3A shows an optical micrograph (OM) of Alloy A1, which
is plant rolled with inter-annealing. FIG. 3B shows a surface
portion from FIG. 3A, showing a recrystallized microstructure. FIG.
3C shows nine black and white reduced-size versions of FIG. 3B,
highlighting various colors shown in FIG. 3B, which may reveal
certain features. FIG. 3D shows a center portion from FIG. 3A,
showing a recovered and/or unrecrystallized microstructure. FIG. 3E
shows nine black and white reduced-size versions of FIG. 3D,
highlighting various colors shown in FIG. 3D, which may reveal
certain features. For example, significant horizontal lines are
shown in the images of FIG. 3E, corresponding to the recovered
and/or unrecrystallized microstructure with various crystal
orientation. For the surface portion shown in FIGS. 3B and 3C,
little of the horizontal structure is seen, indicated significantly
more recrystallized microstructure at the surface portion.
[0016] FIG. 4A shows an optical micrograph of Alloy A5, plant
rolled without inter-annealing during the cold rolling process.
FIG. 4B shows a surface portion from FIG. 4A, showing
recrystallized microstructure. FIG. 4C is from the center portion
from FIG. 4A, showing recovered and/or unrecrystallized
microstructure.
[0017] Cross-sections of aluminum alloy sheet recorded by EBSD are
depicted in the images shown on the right hand side of FIG. 5A,
FIG. 5B, and FIG. 5C, where the aluminum alloy sheet of Alloy A1 is
rolled to a final gauge and finished with a T6 temper. The low
angle boundaries) (2-15.degree. are marked as darker-color
horizontal lines (shown separately in black in the top left images
of FIGS. 5A-5C), while the medium to high angle boundaries
(>15.degree.) are marked as lighter-color horizontal lines (also
shown separately in black the bottom left images of FIGS. 5A-5C).
FIG. 5A is Alloy A1 lab processed, without inter-annealing during
the cold rolling process, which has a uniform microstructure that
is recovered and/or unrecrystallized throughout the whole
thickness, while FIG. 5B is Alloy A1 plant processed, with
inter-annealing during the cold rolling process, which shows a
recrystallization microstructure near the surface and a recovered
and/or unrecrystallized microstructure in the center. FIG. 5C shows
Alloy A5, plant processed, without inter-annealing during the cold
rolling process, which has a microstructure between that shown in
FIG. 5A and FIG. 5B.
[0018] FIG. 6 shows the results of bendability testing for certain
aluminum alloy articles, where bendability is tested in the
longitudinal and transverse direction (relative to the rolling
direction).
[0019] FIG. 7A, FIG. 7B, FIG. 7C, FIG. 7D, and FIG. 7E show
photographs of aluminum alloy sheet following testing for
exfoliation corrosion.
[0020] FIG. 8 shows the results of yield strength testing for a
series of aluminum alloy sheets.
DETAILED DESCRIPTION
[0021] The present disclosure provides aluminum alloy articles that
exhibit a novel combination of recrystallized, and recovered and/or
unrecrystallized, microstructure, and methods of making such
articles. These articles can exhibit increased strength over
articles made from fully recrystallized material, while retaining
the bendability and corrosion resistance that such materials
generally possess.
Definitions and Descriptions
[0022] As used herein, the terms "invention," "the invention,"
"this invention" and "the present invention" are intended to refer
broadly to all of the subject matter of this patent application and
the claims below. Statements containing these terms should be
understood not to limit the subject matter described herein or to
limit the meaning or scope of the patent claims below.
[0023] In this description, reference is made to alloys identified
by AA numbers and other related designations, such as "series" or
"7xxx." For an understanding of the number designation system most
commonly used in naming and identifying aluminum and its alloys,
see "International Alloy Designations and Chemical Composition
Limits for Wrought Aluminum and Wrought Aluminum Alloys" or
"Registration Record of Aluminum Association Alloy Designations and
Chemical Compositions Limits for Aluminum Alloys in the Form of
Castings and Ingot," both published by The Aluminum
Association.
[0024] As used herein, a plate generally has a thickness of greater
than about 15 mm. For example, a plate may refer to an aluminum
product having a thickness of greater than about 15 mm, greater
than about 20 mm, greater than about 25 mm, greater than about 30
mm, greater than about 35 mm, greater than about 40 mm, greater
than about 45 mm, greater than about 50 mm, or greater than about
100 mm.
[0025] As used herein, a shate (also referred to as a sheet plate)
generally has a thickness of from about 4 mm to about 15 mm. For
example, a shate may have a thickness of about 4 mm, about 5 mm,
about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm, about
11 mm, about 12 mm, about 13 mm, about 14 mm, or about 15 mm.
[0026] As used herein, a sheet generally refers to an aluminum
product having a thickness of less than about 4 mm. For example, a
sheet may have a thickness of less than about 4 mm, less than about
3 mm, less than about 2 mm, less than about 1 mm, less than about
0.5 mm, or less than about 0.3 mm (e.g., about 0.2 mm).
[0027] As used herein, the term slab indicates an alloy thickness
in a range of 5 mm to 50 mm. For example, a slab may have a
thickness of about 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm,
40 mm, 45 mm, or 50 mm.
[0028] Reference may be made in this application to alloy temper or
condition. For an understanding of the alloy temper descriptions
most commonly used, see "American National Standards (ANSI) H35 on
Alloy and Temper Designation Systems." An F condition or temper
refers to an aluminum alloy as fabricated. An O condition or temper
refers to an aluminum alloy after annealing. An Hxx condition or
temper, also referred to herein as an H temper, refers to a
non-heat treatable aluminum alloy after cold rolling with or
without thermal treatment (e.g., annealing). Suitable H tempers
include HX1, HX2, HX3 HX4, HX5, HX6, HX7, HX8, or HX9 tempers. A T1
condition or temper refers to an aluminum alloy cooled from hot
working and naturally aged (e.g., at room temperature). A T2
condition or temper refers to an aluminum alloy cooled from hot
working, cold worked and naturally aged. A T3 condition or temper
refers to an aluminum alloy solution heat treated, cold worked, and
naturally aged. A T4 condition or temper refers to an aluminum
alloy solution heat treated and naturally aged. A T5 condition or
temper refers to an aluminum alloy cooled from hot working and
artificially aged (at elevated temperatures). A T6 condition or
temper refers to an aluminum alloy solution heat treated and
artificially aged. A T7 condition or temper refers to an aluminum
alloy solution heat treated and artificially overaged. A T8x
condition or temper refers to an aluminum alloy solution heat
treated, cold worked, and artificially aged. A T9 condition or
temper refers to an aluminum alloy solution heat treated,
artificially aged, and cold worked. A W condition or temper refers
to an aluminum alloy after solution heat treatment.
[0029] As used herein, terms such as "cast metal product," "cast
product," "cast aluminum alloy product," and the like are
interchangeable and refer to a product produced by direct chill
casting (including direct chill co-casting) or semi-continuous
casting, continuous casting (including, for example, by use of a
twin belt caster, a twin roll caster, a block caster, or any other
continuous caster), electromagnetic casting, hot top casting, or
any other casting method.
[0030] As used herein, the meaning of "room temperature" can
include a temperature of from about 15.degree. C. to about
30.degree. C., for example about 15.degree. C., about 16.degree.
C., about 17.degree. C., about 18.degree. C., about 19.degree. C.,
about 20.degree. C., about 21.degree. C., about 22.degree. C.,
about 23.degree. C., about 24.degree. C., about 25.degree. C.,
about 26.degree. C., about 27.degree. C., about 28.degree. C.,
about 29.degree. C., or about 30.degree. C. As used herein, the
meaning of "ambient conditions" can include temperatures of about
room temperature, relative humidity of from about 20% to about
100%, and barometric pressure of from about 975 millibar (mbar) to
about 1050 mbar. For example, relative humidity can be about 20%,
about 21%, about 22%, about 23%, about 24%, about 25%, about 26%,
about 27%, about 28%, about 29%, about 30%, about 31%, about 32%,
about 33%, about 34%, about 35%, about 36%, about 37%, about 38%,
about 39%, about 40%, about 41%, about 42%, about 43%, about 44%,
about 45%, about 46%, about 47%, about 48%, about 49%, about 50%,
about 51%, about 52%, about 53%, about 54%, about 55%, about 56%,
about 57%, about 58%, about 59%, about 60%, about 61%, about 62%,
about 63%, about 64%, about 65%, about 66%, about 67%, about 68%,
about 69%, about 70%, about 71%, about 72%, about 73%, about 74%,
about 75%, about 76%, about 77%, about 78%, about 79%, about 80%,
about 81%, about 82%, about 83%, about 84%, about 85%, about 86%,
about 87%, about 88%, about 89%, about 90%, about 91%, about 92%,
about 93%, about 94%, about 95%, about 96%, about 97%, about 98%,
about 99%, about 100%, or anywhere in between. For example,
barometric pressure can be about 975 mbar, about 980 mbar, about
985 mbar, about 990 mbar, about 995 mbar, about 1000 mbar, about
1005 mbar, about 1010 mbar, about 1015 mbar, about 1020 mbar, about
1025 mbar, about 1030 mbar, about 1035 mbar, about 1040 mbar, about
1045 mbar, about 1050 mbar, or anywhere in between.
[0031] All ranges disclosed herein are to be understood to
encompass any and all subranges subsumed therein. For example, a
stated range of "1 to 10" should be considered to include any and
all subranges between (and inclusive of) the minimum value of 1 and
the maximum value of 10; that is, all subranges beginning with a
minimum value of 1 or more, e.g. 1 to 6.1, and ending with a
maximum value of 10 or less, e.g., 5.5 to 10. Unless stated
otherwise, the expression "up to" when referring to the
compositional amount of an element means that element is optional
and includes a zero percent composition of that particular element.
Unless stated otherwise, all compositional percentages are in
weight percent (wt. %).
[0032] As used herein, the meaning of "a," "an," and "the" includes
singular and plural references unless the context clearly dictates
otherwise.
[0033] In the following examples, the aluminum alloy products and
their components are described in terms of their elemental
composition in weight percent (wt. %). In each alloy, the remainder
is aluminum, with a maximum wt. % of 0.15% for the sum of all
impurities.
[0034] Incidental elements, such as grain refiners and deoxidizers,
or other additives may be present in the invention and may add
other characteristics on their own without departing from or
significantly altering the alloy described herein or the
characteristics of the alloy described herein.
[0035] Unavoidable impurities, including materials or elements may
be present in the alloy in minor amounts due to inherent properties
of aluminum or leaching from contact with processing equipment.
Some impurities typically found in aluminum include iron and
silicon. The alloy, as described, may contain no more than about
0.25 wt. % of any element besides the alloying elements, incidental
elements, and unavoidable impurities.
Aluminum Alloy Article
[0036] In at least one aspect, the present disclosure provides an
aluminum alloy article, comprising an aluminum alloy material and
having a first surface portion; a second surface portion opposing
the first surface portion; and an intermediate portion between the
first surface portion and the second surface portion; wherein the
aluminum alloy material of the first surface portion and the second
surface portion have a higher degree of recrystallization or
recrystallization quotient than the aluminum alloy material of the
intermediate portion. In some embodiments thereof, the first
surface portion and the second surface portion each comprise a
rolled surface.
[0037] The aluminum alloy article can comprise any suitable
aluminum alloy material ranging from 1xxx series aluminum alloys to
8xxx series aluminum alloys. In some embodiments, the aluminum
alloy material is a 5xxx series aluminum alloy, a 6xxx series
aluminum alloy, or a 7xxx series aluminum alloy. In some
embodiments, the aluminum alloy material is a 7xxx series aluminum
alloy that comprises, among other standard elements, an amount of
zirconium (Zr), for example, from 0.01 wt. % to 0.50 wt. %, based
on the total elemental composition of the alloy.
[0038] In some embodiments where the aluminum alloy material is a
7xxx series aluminum alloy, the aluminum alloy material can be
selected from any suitable 7xxx series aluminum alloy, including,
but not limited to, the following 7xxx series aluminum alloys:
AA7011, AA7019, AA7020, AA7021, AA7039, AA7072, AA7075, AA7085,
AA7108, AA7108A, AA7015, AA7017, AA7018, AA7019A, AA7024, AA7025,
AA7028, AA7030, AA7031, AA7033, AA7035, AA7035A, AA7046, AA7046A,
AA7003, AA7004, AA7005, AA7009, AA7010, AA7011, AA7012, AA7014,
AA7016, AA7116, AA7122, AA7023, AA7026, AA7029, AA7129, AA7229,
AA7032, AA7033, AA7034, AA7036, AA7136, AA7037, AA7040, AA7140,
AA7041, AA7049, AA7049A, AA7149,7204, AA7249, AA7349, AA7449,
AA7050, AA7050A, AA7150, AA7250, AA7055, AA7155, AA7255, AA7056,
AA7060, AA7064, AA7065, AA7068, AA7168, AA7175, AA7475, AA7076,
AA7178, AA7278, AA7278A, AA7081, AA7181, AA7185, AA7090, AA7093,
AA7095, and AA7099.
[0039] In some embodiments, the aluminum alloy material has the
elemental composition set forth in Table 1.
TABLE-US-00001 TABLE 1 Element Weight Percentage (wt. %) Zn
4.0-15.0 Cu 0.1-3.5 Mg 1.0-4.0 Fe 0.05-0.50 Si 0.05-0.30 Zr
0.01-0.50 Mn 0-0.25 Cr 0-0.20 Ti 0-0.15 Impurities 0-0.15 Al
Remainder
[0040] In some embodiments, the aluminum alloy material has the
elemental composition set forth in Table 2.
TABLE-US-00002 TABLE 2 Element Weight Percentage (wt. %) Zn 5.6-9.3
Cu 0.2-2.6 Mg 1.4-2.8 Fe 0.10-0.35 Si 0.05-0.20 Zr 0.05-0.25 Mn
0-0.05 Cr 0-0.10 Ti 0-0.05 Impurities 0-0.15 Al Remainder
[0041] Optionally, the aluminum alloy material includes zinc (Zn)
in an amount of from 4% to 15% (e.g., from 5.4% to 9.5%, from 5.6%
to 9.3%, from 5.8% to 9.2%, or from 4.0% to 5.0%) based on the
total weight of the alloy. For example, the aluminum alloy material
can include 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%,
4.9%, 5.0%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9%,
6.0%, 6.1%, 6.2%, 6.3%, 6.4%, 6.5%, 6.6%, 6.7%, 6.8%, 6.9%, 7.0%,
7.1%, 7.2%, 7.3%, 7.4%, 7.5%, 7.6%, 7.7%, 7.8%, 7.9%, 8.0%, 8.1%,
8.2%, 8.3%, 8.4%, 8.5%, 8.6%, 8.7%, 8.8%, 8.9%, 9.0%, 9.1%, 9.2%,
9.3%, 9.4%, 9.5%, 9.6% 9.7%, 9.8%, 9.9%, 10.0%, 10.1%, 10.2%,
10.3%, 10.4%, 10.5%, 10.6%, 10.7%, 10.8%, 10.9%, 11.0%, 11.1%,
11.2%, 11.3%, 11.4%, 11.5%, 11.6%, 11.7%, 11.8%, 11.9%, 12.0%,
12.1%, 12.2%, 12.3%, 12.4%, 12.5%, 12.6%, 12.7%, 12.8%, 12.9%,
13.0%, 13.1%, 13.2%, 13.3%, 13.4%, 13.5%, 13.6%, 13.7%, 13.8%,
13.9%, 14.0%, 14.1%, 14.2%, 14.3%, 14.4%, 14.5%, 14.6%, 14.7%,
14.8%, 14.9%, or 15.0% Zn. All are expressed in wt. %.
[0042] Optionally, the aluminum alloy material includes copper (Cu)
in an amount of from 0.1% to 3.5% (e.g., from 0.2% to 2.6%, from
0.3% to 2.5%, or from 0.15% to 0.6%) based on the total weight of
the alloy. For example, the aluminum alloy material can include
0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%,
0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%,
0.28%, 0.29%, 0.30%, 0.35%, 0.40%, 0.45%, 0.50%, 0.55%, 0.60%,
0.65%, 0.70% 0.75%, 0.80%, 0.85%, 0.90%, 0.95%, 1.0%, 1.1%, 1.2%,
1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%,
2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%,
or 3.5% Cu. All are expressed in wt. %.
[0043] Optionally, the aluminum alloy material includes magnesium
(Mg) in an amount of from 1.0% to 4.0% (e.g., from 1.0% to 3.0%,
from 1.4% to 2.8%, or from 1.6% to 2.6%). For example, the aluminum
alloy material can include 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%,
1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%,
2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%,
3.8%, 3.9%, or 4.0% Mg. All are expressed in wt. %.
[0044] Optionally, the aluminum alloy material includes a combined
content of Zn, Cu, and Mg ranging from 5% to 14% (e.g., from 5.5%
to 13.5%, from 6% to 13%, from 6.5% to 12.5%, or from 7% to 12%).
For example, the combined content of Zn, Cu, and Mg can be 5.0%,
5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, 10.0%, 10.5%,
11.0%, 11.5%, 12.0%, 12.5%, 13.0%, 13.5%, or 14.0%. All are
expressed in wt. %.
[0045] Optionally, the aluminum alloy material includes iron (Fe)
in an amount of from 0.05% to 0.50% (e.g., from 0.10% to 0.35% or
from 0.10% to 0.25%) based on the total weight of the alloy. For
example, the aluminum alloy material can include 0.05%, 0.06%,
0.07%, 0.08%, 0.09%, 0.10% 0.11%, 0.12%, 0.13%, 0.14%, 0.15%,
0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%,
0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%,
0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.40%, 0.41%, 0.42%,
0.43%, 0.44% 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, or 0.50% Fe. All
are expressed in wt. %.
[0046] Optionally, the aluminum alloy material includes silicon
(Si) in an amount of from 0.05% to 0.30% (e.g., from 0.05% to 0.25%
or from 0.07% to 0.15%) based on the total weight of the alloy. For
example, the aluminum alloy material can include 0.05%, 0.06%,
0.07%, 0.08%, 0.09%, 0.10% 0.11%, 0.12%, 0.13%, 0.14%, 0.15%,
0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%,
0.25%, 0.26%, 0.27%, 0.28%, 0.29%, or 0.30% Si. All are expressed
in wt. %.
[0047] Optionally, the aluminum alloy material includes zirconium
(Zr) in an amount of from 0.01% to 0.50% (e.g., from 0.05% to
0.25%, or from 0.05% to 0.20% or from 0.09% to 0.15%) based on the
total weight of the alloy. For example, the aluminum alloy material
can include 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%,
0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%,
0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%,
0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%,
0.36%, 0.37%, 0.38%, 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%,
0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50% Zr. In other examples, the
alloys can include Zr in an amount less than 0.05% (e.g., 0.04%,
0.03%, 0.02%, or 0.01%) based on the total weight of the alloy. All
are expressed in wt. %.
[0048] In some instances, the presence of Zr in the alloy may form
Al.sub.3Zr dispersoids, which can assist in pinning the grain
boundaries of the aluminum alloy material. In the region of the
aluminum alloy article near a rolled surface, the higher strain
introduced from the rolling process can at least partially overcome
the pinning and allow for a higher degree of recrystallization or
recrystallization quotient. Meanwhile, in the interior portions of
the aluminum alloy article, the pinning is not overcome and
recrystallization occurs to a much lower degree. In some
embodiments, Al.sub.3Zr dispersoids are present in the aluminum
alloy material, the dispersoids having a number-average diameter
ranging from 1 nm to 20 nm.
[0049] Optionally, the aluminum alloy material includes manganese
(Mn) in an amount of up to 0.25% (e.g., from 0.01% to 0.10% or from
0.02% to 0.05%) based on the total weight of the alloy. For
example, the aluminum alloy material can include 0.01%, 0.02%,
0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%,
0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%,
0.21%, 0.22%, 0.23%, 0.24%, or 0.25% Mn. In some cases, Mn is not
present in the alloy (i.e., 0%). All are expressed in wt. %.
[0050] Optionally, the aluminum alloy material includes chromium
(Cr) in an amount of up to 0.20%, or up to 0.10% (e.g., from 0.01%
to 0.10%, from 0.01% to 0.05%, or from 0.03% to 0.05%) based on the
total weight of the alloy. For example, the aluminum alloy material
can include 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%,
0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%,
0.18%, 0.19%, or 0.20% Cr. In some cases, Cr is not present in the
alloy (i.e., 0%). All are expressed in wt. %.
[0051] Optionally, the aluminum alloy material includes titanium
(Ti) in an amount of up to 0.15% (e.g., from 0.001% to 0.10%, from
0.001% to 0.05%, or from 0.003% to 0.035%) based on the total
weight of the alloy. For example, the alloy can include 0.001%,
0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%,
0.010%, 0.011% 0.012%, 0.013%, 0.014%, 0.015%, 0.016%, 0.017%,
0.018%, 0.019%, 0.020%, 0.021% 0.022%, 0.023%, 0.024%, 0.025%,
0.026%, 0.027%, 0.028%, 0.029%, 0.030%, 0.031%, 0.032%, 0.033%,
0.034%, 0.035%, 0.036%, 0.037%, 0.038%, 0.039%, 0.040%, 0.041%,
0.042%, 0.043%, 0.044%, 0.045%, 0.046%, 0.047%, 0.048%, 0.049%,
0.050%, 0.055%, 0.060%, 0.065%, 0.070%, 0.075%, 0.080%, 0.085%,
0.090%, 0.095%, 0.100%, 0.110%, 0.120%, 0.130%, 0.140%, or 0.150%
Ti. In some cases, Ti is not present in the alloy (i.e., 0%). All
are expressed in wt. %.
[0052] Optionally, the aluminum alloy material includes one or more
elements selected from the group consisting of Y, La, Ce, Pr, Nd,
Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu in an amount of up
to 0.10% (e.g., from 0.01% to 0.10%, from 0.01% to 0.05%, or from
0.03% to 0.05%), based on the total weight of the alloy. For
example, the aluminum alloy material can include 0.01%, 0.02%,
0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.10% of one or
more elements selected from the group consisting of Y, La, Ce, Pr,
Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. All are
expressed in wt. %.
[0053] Optionally, the aluminum alloy material includes one or more
elements selected from the group consisting of Mo, Nb, Be, B, Co,
Sn, Sr, V, In, Hf, Ag, Sc, and Ni in an amount of up to 0.10%
(e.g., from 0.01% to 0.10%, from 0.01% to 0.05%, or from 0.03% to
0.05%), based on the total weight of the alloy. For example, the
aluminum alloy material can include 0.01%, 0.02%, 0.03%, 0.04%,
0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.10% of one or more elements
selected from the group consisting of Mo, Nb, Be, B, Co, Sn, Sr, V,
In, Hf, Ag, Sc, and Ni. All are expressed in wt. %.
[0054] Optionally, the aluminum alloy material includes other minor
elements, sometimes referred to as impurities, in amounts of 0.15%
or below, 0.14% or below, 0.13% or below, 0.12% or below, 0.11% or
below, 0.10% or below, 0.09% or below, 0.08% or below, 0.07% or
below, 0.06% or below, 0.05% or below, 0.04% or below, 0.03% or
below, 0.02% or below, or 0.01% or below. In some embodiments,
these impurities include, but are not limited to, Ga, Ca, Bi, Na,
Pb, or combinations thereof. Accordingly, in some embodiments, one
or more elements selected from the group consisting of Ga, Ca, Bi,
Na, and Pb may be present in the aluminum alloy material in amounts
of 0.15% or below, 0.14% or below, 0.13% or below, 0.12% or below,
0.11% or below, 0.10% or below, 0.09% or below, 0.08% or below,
0.07% or below, 0.06% or below, 0.05% or below, 0.04% or below,
0.03% or below, 0.02% or below, or 0.01% or below. The sum of all
impurities does not exceed 0.15% (e.g., 0.10%). All are expressed
in wt. %. The remaining percentage of the alloy is aluminum.
[0055] The alloy compositions disclosed herein, including the
aluminum alloy material of any of foregoing embodiments, have
aluminum (A1) as a major component, for example, in an amount of at
least 85.0% of the alloy. Optionally, the alloy compositions have
at least 85.5% A1, or at least 86.0% A1, or at least 86.5% A1, or
at least 87.0% A1, or at least 87.5% A1, or at least 88.0% A1, or
at least 88.5% A1, or at least 89.0% A1, or at least 89.5% A1, or
at least 90.0% A1, or at least 90.5% A1, or at least 91.0% A1, or
at least 91.5% A1, or at least 92.0% A1. All are expressed in wt.
%.
[0056] The aluminum alloy articles disclosed herein can be any
suitable aluminum alloy article. As noted above, the articles have
a first surface portion and an opposing second surface portion. In
some cases, the surface of the first surface portion and the
surface of the second surface portion represent opposite sides of
an article, such that the two surfaces may be parallel or generally
parallel to each other or disposed away from each other and
separated by a thickness, e.g., a first thickness, which may
represent a distance between the two surfaces along a line
perpendicular to the two surfaces or the shortest distance between
the two surfaces.
[0057] As noted above, in some embodiments, the first surface
portion comprises a rolled surface and the second surface portion
comprises a rolled surface, for example, the surfaces of an article
formed by rolling a cast aluminum product, such as a slab, an
ingot, a shate, a sheet, a plate and the like. In some embodiments,
these rolled surfaces are formed according to the processes set
forth below. For example, the rolled surface of the first surface
portion and the rolled surface of the second surface portion may be
formed by a process that comprises cold rolling. In some
embodiments, the cold rolling is preceded by hot rolling. In some
embodiments, the cold rolling is preceded by hot rolling.
[0058] The aluminum alloy article can have any suitable physical
configuration. Optionally, the aluminum alloy article is a rolled
aluminum alloy plate, shate or sheet. In some embodiments, the
aluminum alloy article is a rolled aluminum alloy shate. The rolled
aluminum alloy shate can have any suitable thickness, but, in some
embodiments, it has a thickness ranging from 4 mm to 15 mm, or no
more than 14 mm, or no more than 13 mm, or no more than 12 mm, or
no more than 11 mm, or no more than 10 mm, or no more than 9 mm, or
no more than 8 mm, or no more than 7 mm, or no more than 6 mm, or
no more than 5 mm. In some embodiments, the aluminum alloy article
is a rolled aluminum alloy sheet. The rolled aluminum alloy sheet
can have any suitable thickness, but, in some embodiments, it has a
thickness ranging from 0.05 mm to 4 mm, or no more than 3 mm, or no
more than 2 mm, or no more than 1 mm, or no more than 0.5 mm, or no
more than 0.3 mm, or no more than 0.1 mm. In some embodiments, the
aluminum alloy article is a rolled aluminum alloy shate or a rolled
aluminum alloy sheet having a thickness of 15 mm, or 14 mm, or 13
mm, or 12 mm, or 11 mm, or 10 mm, or 9 mm, or 8 mm, or 7 mm, or 6
mm, or 5 mm, or 4 mm, or 3 mm, or 2 mm, or 1 mm, or 0.5 mm, or 0.3
mm, or 0.1 mm.
[0059] The disclosure refers to certain "surface portion(s)," such
as a first surface portion and a second surface portion. Such
surface portions include a surface of the article, such as a rolled
surface, and a certain amount of material (e.g., a uniform depth of
material) beneath the surface and along the thickness of the
article (i.e., the line running perpendicular to the respective
surfaces of the first surface portion and the second surface
portion). Optionally, the first surface portion extends from the
surface of the first surface portion to a depth of no more than
40.0%, or no more than 35.0%, or no more than 33.3%, or no more
than 30.0%, or no more than 25.0%, or no more than 20.0%, or no
more than 15.0%, or no more than 10.0%, of the thickness of the
aluminum alloy article. In some embodiments, the second surface
portion extends from the surface of the second surface portion to a
depth of no more than 40.0%, or no more than 35.0%, or no more than
33.3%, or no more than 30.0%, or no more than 25.0%, or no more
than 20.0%, or no more than 15.0%, or no more than 10.0%, of the
thickness of the aluminum alloy article. In some embodiments, the
first surface portion and the second surface portion are of the
same depth, i.e., are symmetrical in depth with respect to the
midpoint of the distance between the two surfaces. In some other
embodiments, however, the first surface portion and the second
surface portion have different depths.
[0060] The disclosure also refers to an "intermediate portion" that
lies between the first surface portion and the second surface
portion. Optionally, the intermediate portion includes the
remaining material between the two surfaces that is not included in
the first surface portion and the second surface portion, such that
the intermediate portion extends from the depth of the first
surface portion to the depth of the second surface portion. Thus,
in some embodiments, all material between the two surfaces is
included in either the first surface portion, the second surface
portion, or the intermediate portion. Optionally, the intermediate
portion does not include all of the remaining material between the
two surfaces that is not included in the first surface portion and
the second surface portion. In some embodiments, the intermediate
portion lies between the depth of the first surface portion and the
depth of the second surface portion, includes the midpoint in the
thickness between the depth of the first surface portion and the
depth of the second surface portion, and includes no more than
10.0%, or no more than 20.0%, or no more than 30.0%, or no more
than 40.0%, or no more than 50.0%, or no more than 60.0%, or no
more than 70.0%, or no more than 80.0%, or no more than 90.0%, or
no more than 95.0%, or no more than 97.0%, or no more than 99.0%,
of the thickness between the depth of the first surface portion and
the depth of the second surface portion. In some embodiments, the
midpoint in the thickness between the depth of the first surface
portion and the depth of the second surface portion lies at the
midpoint in the thickness of the intermediate portion.
[0061] The disclosure provides aluminum alloy articles in which the
aluminum alloy material of the first surface portion has a higher
degree of recrystallization or recrystallization quotient than the
aluminum alloy material of the intermediate portion. In some
embodiments, the second surface portion also has a higher degree of
recrystallization or recrystallization quotient than the aluminum
alloy material of the intermediate portion, such that, in the case
of an aluminum alloy plate, shate or sheet, the areas nearer to the
two surfaces of the plate, shate or sheet have a higher degree of
recrystallization or recrystallization quotient than the area lying
in the interior of the plate, shate or sheet.
[0062] The degree of recrystallization or recrystallization
quotient can be determined by any suitable method known in the art.
For example, in a micrograph, such as a scanning electron
micrograph (SEM) or an optical micrograph (OM), the higher degree
of recrystallization recrystallization quotient can be observed in
terms of a grain structure having a higher degree of uniformity. In
some other examples, electron backscatter diffraction (EBSD) can
also be used to assess the degree of recrystallization. Optionally,
the degree of recrystallization is set forth in terms of a
"recrystallization quotient," which, as used herein, refers to the
formula: 1-LAGB/(MAGB+HAGB). In some embodiments, a
recrystallization quotient may refer to or be representative of a
percentage, amount, or volume of material that is recrystallized as
compared to a total amount or volume of material. LAGB refers to
the quantity of grain boundaries in a given volume having
misorientation between adjacent grains of 2.degree. to 15.degree.
(i.e., a quantity of low-angle grain boundaries). MAGB refers to
the quantity of grain boundaries in a given volume having
misorientation between adjacent grains of greater than 15.degree.
but no more than 30.degree. (i.e., the quantity of medium-angle
grain boundaries). HAGB refers to the quantity of grain boundaries
in a given volume having misorientation between adjacent grains of
more than 30.degree. (i.e., the quantity of high-angle grain
boundaries). Quantities or values of LAGB, MAGB, and HAGB may be
determined by measuring the angle of misorientation between
adjacent grains, as recorded by EBSD. The recovery or
recrystallization of materials may reduce the stored energy in
materials when heavily deformed materials are annealed at high
temperature. Recovery competes with recrystallization, as both are
driven by the stored energy during annealing. Recovery can be
defined as annealing processes occurring in deformed materials that
occur without the migration of a high-angle grain boundary. The
deformed structure is often a cellular structure with walls having
dislocation angles. As recovery proceeds, these cell walls undergo
a transition towards a genuine subgrain structure. This occurs
through a gradual elimination of extraneous dislocations and the
rearrangement of the remaining dislocations into low-angle grain
boundaries. However, recrystallization is the formation of a new
grain structure in a deformed material by the formation and
migration of high angle grain boundaries driven by the stored
energy of deformation. Therefore, the LAGB is eliminated during the
recrystallization process.
[0063] Optionally, the aluminum alloy material of the first surface
portion has a recrystallization quotient that is higher than the
recrystallization quotient of the aluminum alloy material of the
intermediate portion. Optionally, the first surface portion has a
recrystallization quotient that at least 0.01 higher (e.g.,
0.01-1.0), or at least 0.03 higher, or at least 0.05 higher, or at
least 0.07 higher, or at least 0.10 higher, or at least 0.15
higher, or at least 0.20 higher, or at least 0.25 higher, or at
least 0.30 higher, or at least 0.35 higher, or at least 0.40
higher, or at least 0.45 higher, or at least 0.50 higher, than the
recrystallization quotient of the aluminum alloy material of the
intermediate portion.
[0064] Optionally, the aluminum alloy material of the second
surface portion has a recrystallization quotient that is higher
than the recrystallization quotient of the aluminum alloy material
of the intermediate portion. Optionally, the second surface portion
has a recrystallization quotient that at least 0.01 higher (e.g.,
0.01-1.0), or at least 0.03 higher, or at least 0.05 higher, or at
least 0.07 higher, or at least 0.10 higher, or at least 0.15
higher, or at least 0.20 higher, or at least 0.25 higher, or at
least 0.30 higher, or at least 0.35 higher, or at least 0.40
higher, or at least 0.45 higher, or at least 0.50 higher, than the
recrystallization quotient of the aluminum alloy material of the
intermediate portion.
[0065] Optionally, the aluminum alloy material of the first surface
portion has a recrystallization quotient of at least 0.50, or at
least 0.55, or at least 0.60, or at least 0.65, or at least 0.70,
or at least 0.75, or at least 0.80, or at least 0.85, or at least
0.90. For example, the first surface portion may have a
recrystallization quotient of 0.5 to 1.0.
[0066] Optionally, the aluminum alloy material of the second
surface portion has a recrystallization quotient of at least 0.50,
or at least 0.55, or at least 0.60, or at least 0.65, or at least
0.70, or at least 0.75, or at least 0.80, or at least 0.85, or at
least 0.90. For example, the second surface portion may have a
recrystallization quotient of 0.5 to 1.0.
[0067] Optionally, the aluminum alloy material of the intermediate
portion has a recrystallization quotient of no more than 0.25, or
no more than 0.30, or no more than 0.35, or no more than 0.40, or
no more than 0.45, or no more than 0.50, or no more than 0.55, or
no more than 0.60, or no more than 0.65. For example, the
intermediate portion may have a recrystallization quotient of 0 to
0.65 or 0.01 to 0.65.
[0068] Optionally, the aluminum alloy article, when subjected to
bendability testing according to Specification VDA 238-100, has a
.beta. angle of no more than 138.degree., or no more than
137.degree., no more than 136.degree., no more than 135.degree., no
more than 134.degree., no more than 133.degree., no more than
132.degree., or no more than 131.degree., such as between
100.degree. and 142.degree..
[0069] Optionally, the aluminum alloy article, when subjected to
exfoliation corrosion testing according to ASTM Test No. G34-01,
has an exfoliation corrosion rating of EA.
Methods of Preparing Aluminum Alloy Articles
[0070] In certain aspects, the disclosed aluminum alloy articles
are products of a disclosed method. Without intending to limit the
scope of the inventions set forth herein, the properties of the
aluminum alloy articles set forth herein are partially determined
by the formation of certain microstructures during the preparation
thereof.
[0071] In at least one aspect, the disclosure provides a method of
making an aluminum alloy article, the method comprising: providing
an aluminum alloy in a molten state as a molten aluminum alloy;
casting the molten aluminum alloy to form an aluminum alloy cast
product; homogenizing the aluminum alloy cast product to form a
homogenized aluminum alloy cast product; rolling the homogenized
aluminum alloy cast product to form a first rolled aluminum alloy
product having a first thickness, wherein the rolling comprises one
or more hot rolling passes and one or more cold rolling passes,
wherein the one or more hot rolling passes precede the one or more
cold rolling passes; annealing the first rolled aluminum alloy
product at a temperature of not more than 50.degree. C. above the
minimum recrystallization temperature of the aluminum alloy to form
a first annealed aluminum product; and rolling the first annealed
aluminum alloy product to form a second rolled aluminum product
having a second thickness.
[0072] FIG. 1 provides an overview of a method of making an
aluminum alloy article. The method of FIG. 1 begins at step 105
where an aluminum alloy 106 is cast to form an aluminum alloy cast
product 107, such as an ingot or other cast product. At step 110
the aluminum alloy cast product 107 is homogenized to form a
homogenized aluminum alloy cast product 111. At step 115, the
homogenized aluminum alloy cast product 111 is subjected to one or
more hot rolling passes and one or more cold rolling passes to form
a first rolled aluminum alloy product 112. At step 120, the first
rolled aluminum alloy product 112 is annealed to form a first
annealed aluminum alloy product 121. At step 125, the first
annealed aluminum alloy product 121 is subjected to a second
rolling process to form a second rolled aluminum product 126, which
may correspond to an aluminum alloy article. Optionally, the second
rolled aluminum product 126 is subjected to one or more additional
forming or stamping processes to form an aluminum alloy
article.
Casting
[0073] The methods disclosed herein may comprise a step of casting
a molten aluminum alloy to form an aluminum alloy cast product. In
some embodiments, the molten alloy may be treated before casting.
The treatment can include one or more of degassing, inline fluxing,
and filtering. Aluminum alloy cast products can be formed using any
casting process performed according to standards commonly used in
the aluminum industry as known to one of ordinary skill in the
art.
[0074] As a few non-limiting examples, the casting process can
include a Direct Chill (DC) casting process or a Continuous Casting
(CC) process. The continuous casting system can include a pair of
moving opposed casting surfaces (e.g., moving opposed belts, rolls
or blocks), a casting cavity between the pair of moving opposed
casting surfaces, and a molten metal injector. The molten metal
injector can have an end opening from which molten metal can exit
the molten metal injector and be injected into the casting cavity.
In some embodiments, the CC process may include, but is not limited
to, the use of twin-belt casters, twin-roll casters, or block
casters. In some embodiments, the casting process is performed by a
CC process to form a cast product in the form of a billet, a slab,
a shate, a strip, and the like.
[0075] A clad layer in a cast product may be attached to a core
layer in a cast product to form a cladded product by any means
known to persons of ordinary skill in the art. For example, a clad
layer can be attached to a core layer by direct chill co-casting
(i.e., fusion casting) as described in, for example, U.S. Pat. Nos.
7,748,434 and 8,927,113, both of which are hereby incorporated by
reference in their entireties; by hot and cold rolling a composite
cast ingot as described in U.S. Pat. No. 7,472,740, which is hereby
incorporated by reference in its entirety; or by roll bonding to
achieve the required metallurgical bonding between the core and the
cladding. The initial dimensions and final dimensions of the clad
aluminum alloy products described herein can be determined by the
desired properties of the overall final product.
[0076] The roll bonding process can be carried out in different
manners, as known to those of ordinary skill in the art. For
example, the roll-bonding process can include both hot rolling and
cold rolling. Further, the roll bonding process can be a one-step
process or a multi-step process in which the material is gauged
down during successive rolling steps. Separate rolling steps can
optionally be separated by other processing steps, including, for
example, annealing steps, cleaning steps, heating steps, cooling
steps, and the like.
[0077] A cast product, such as an ingot, billet, slab, shate,
strip, etc., can be processed by any means known to those of
ordinary skill in the art. Optionally, the processing steps can be
used to prepare sheets. Such processing steps include, but are not
limited to, homogenization, hot rolling, cold rolling, solution
heat treatment, and an optional pre-aging step, as known to those
of ordinary skill in the art. The processing steps can be suitably
applied to any cast product, including, but not limited to, ingots,
billets, slabs, strips, plates, shates, etc., using modifications
and techniques as known to those of skill in the art. Specific
processing steps may be used to prepare aluminum alloy articles
with particular recrystallization quotient distributions, as
described below.
[0078] In some cases, the casting process may impact the
recrystallization and reforming that may occur during subsequent
processing steps. For example, the distribution of
dispersoid-forming elements in a cast product, such as an ingot,
may impact the ability of a cast product to undergo
recrystallization. By selectively segregating dispersoid-forming
elements during the casting process, different regions of the cast
products and processed products and articles may be more or less
prone to undergo recrystallization. Dispersoid forming elements
include, for example, Mn, Cr, Ti, Zr, and Sc, which may precipitate
out of supersaturated solutions in the form of nano-scale
precipitates, which may be, for example, from 10 nm in diameter to
30 nm in diameter. These precipitates may have sizes that do not
promote recrystallization nucleation in the way that larger
particles do. Instead, these particles may inhibit the motion of
dislocations and grain boundaries such that recrystallization is
inhibited. The volume or mass fraction of these dispersoids may
determine or impact the specific recrystallization behavior in a
cast product.
[0079] In large-scale castings, depletion or accumulation of
alloying elements can occur. This is known as macrosegregation,
which may be caused by the relative movement of solid and liquid
phases which are of inherently different compositions. The center
of an ingot may be particularly susceptible to macrosegregation,
such as during casting. For example, this area of an ingot may
exhibit depletion of eutectic forming elements, with the relative
depletion proportional to casting speed. This property is further
elucidated by Yu and Granger in "Macrosegregation in Aluminum Alloy
Ingot Cast by the Semicontinuous Direct Chill (DC) Method,
International Conference on Aluminum alloys--Their physical and
mechanical properties, Charlottesville, Va. Warley (UK): EMAS;
1986, p. 17-29.
[0080] Similarly, dispersoid forming elements may also be
selectively enriched in the centerline, and the enrichment may also
be enhanced by increasing the casting speed. Thus, by varying the
casting speed, the distributions of dispersoid-forming elements may
be optimized at the center of the ingot, which can impact the rate
at which recrystallization may occur. For example, by increasing
the casting speed in an ingot containing dispersoid-forming
elements, their concentration at the center of the ingot may be
increased as compared to slower casting rates. The enhanced
dispersoid content in the corresponding solidified ingot can then
be used during subsequent processing steps (e.g., rolling,
annealing, etc.) to impact the rate of recrystallization at the
center of a processed object. In this way, casting can impact the
amount and rate of recrystallization at an intermediate portion
relative to surface portions during subsequent rolling and
annealing steps, for example. Accordingly, methods disclosed herein
may optionally utilize a high-rate casting step, such as greater
than about 1.5 inches per minute (IPM), such as 1.5-10 IPM, 2.5-10
IPM, 3.5-10 IPM, or 4.5-10 IPM.
Stress Relieving
[0081] The methods disclosed herein can also optionally comprise a
stress relieving step, which includes heating the aluminum alloy
cast product prepared from an alloy composition described herein to
attain a peak metal temperature (PMT) of at least 300.degree. C. up
to 420.degree. C. In some embodiments, the stress relieving is
carried out at a temperature of 300.degree. C., or 310.degree. C.,
or 320.degree. C., or 330.degree. C., or 340.degree. C., or
350.degree. C., or 360.degree. C., or 370.degree. C., or
380.degree. C., or 390.degree. C., or 400.degree. C., or
410.degree. C., or 420.degree. C. In general, the heating is
carried out for a period of at least 8 hours and up to, for
example, 24 hours. In some embodiments, the heating is carried out
for 8 hours, or 9 hours, or 10 hours, or 11 hours, or 12 hours, or
13 hours, or 14 hours, or 15 hours, or 16 hours, or 17 hours, or 18
hours, or 19 hours, or 20 hours, or 21 hours, or 22 hours, or 23
hours, or 24 hours. During stress relieving, the microstructure of
an aluminum alloy cast or rolled product may be modified, such as
by a recrystallization process or recovery process.
Homogenization
[0082] The homogenization step can include heating an aluminum
alloy cast product prepared from an alloy composition described
herein to attain a peak metal temperature (PMT) of at least
450.degree. C. (e.g., at least 450.degree. C., at least 460.degree.
C., at least 470.degree. C., at least 480.degree. C., at least
490.degree. C., at least 500.degree. C., at least 510.degree. C.,
at least 520.degree. C., at least 530.degree. C., at least
540.degree. C., at least 550.degree. C., at least 560.degree. C.,
at least 570.degree. C., or at least 580.degree. C.). For example,
the aluminum alloy product can be heated to a temperature of from
520.degree. C. to 580.degree. C., from 530.degree. C. to
575.degree. C., from 535.degree. C. to 570.degree. C., from
540.degree. C. to 565.degree. C., from 545.degree. C. to
560.degree. C., from 530.degree. C. to 560.degree. C., or from
550.degree. C. to 580.degree. C. Optionally, the heating rate to
the PMT is 100.degree. C./hour or less, 75.degree. C./hour or less,
50.degree. C./hour or less, 40.degree. C./hour or less, 30.degree.
C./hour or less, 25.degree. C./hour or less, 20.degree. C./hour or
less, or 15.degree. C./hour or less. Optionally, the heating rate
to the PMT is from 10.degree. C./min to 100.degree. C./min (e.g.,
10.degree. C./min to 90.degree. C./min, 10.degree. C./min to
70.degree. C./min, 10.degree. C./min to 60.degree. C./min, from
20.degree. C./min to 90.degree. C./min, from 30.degree. C./min to
80.degree. C./min, from 40.degree. C./min to 70.degree. C./min, or
from 50.degree. C./min to 60.degree. C./min).
[0083] In some instances, the aluminum alloy cast product is then
allowed to soak (i.e., held at a particular temperature, such as a
PMT) for a period of time. In some embodiments, the aluminum alloy
cast product is allowed to soak for up to 15 hours (e.g., from 30
minutes to 6 hours, inclusively). For example, in some embodiments,
the aluminum alloy product is soaked at a temperature of at least
450.degree. C. for 30 minutes, for 1 hour, for 2 hours, for 3
hours, for 4 hours, for 5 hours, for 6 hours, for 7 hours, for 8
hours, for 9 hours, for 10 hours, for 11 hours, for 12 hours, for
13 hours, for 14 hours, for 15 hours, or for any time period in
between.
[0084] In some embodiments, the homogenization described herein can
be carried out in a two-stage homogenization process. In some
embodiments, the homogenization process can include the
above-described heating and soaking steps, which can be referred to
as the first stage, and can further include a second stage. In the
second stage of the homogenization process, the temperature of the
aluminum alloy cast product is increased to a temperature higher
than the temperature used for the first stage of the homogenization
process. The aluminum alloy cast product temperature can be
increased, for example, to a temperature at least 5.degree. C.
higher than the aluminum alloy cast product temperature during the
first stage of the homogenization process. For example, the
aluminum alloy cast product temperature can be increased to a
temperature of at least 455.degree. C. (e.g., at least 460.degree.
C., at least 465.degree. C., or at least 470.degree. C.). The
heating rate to the second stage homogenization temperature can be
5.degree. C./hour or less, 3.degree. C./hour or less, or
2.5.degree. C./hour or less. The aluminum alloy cast product is
then allowed to soak for a period of time during the second stage.
In some embodiments, the aluminum alloy cast product is allowed to
soak for up to 10 hours (e.g., from 30 minutes to 10 hours,
inclusively). For example, the aluminum alloy cast product can be
soaked at the temperature of at least 455.degree. C. for 30
minutes, for 1 hour, for 2 hours, for 3 hours, for 4 hours, for 5
hours, for 6 hours, for 7 hours, for 8 hours, for 9 hours, or for
10 hours. In some embodiments, following homogenization, the
aluminum alloy cast product is allowed to cool to room temperature
in the air.
Hot Rolling
[0085] Following the homogenization step, one or more hot rolling
passes may be performed. In certain cases, the aluminum alloy
products are laid down and hot rolled at a temperature ranging from
250.degree. C. to 550.degree. C. (e.g., from 300.degree. C. to
500.degree. C., or from 350.degree. C. to 450.degree. C.).
[0086] In certain embodiments, the aluminum alloy product is hot
rolled to a 4 mm to 15 mm thick gauge (e.g., from 5 mm to 12 mm
thick gauge), which is referred to as a shate. For example, the
aluminum alloy product can be hot rolled to a 15 mm thick gauge, a
14 mm thick gauge, a 13 mm thick gauge, a 12 mm thick gauge, a 11
mm thick gauge, a 10 mm thick gauge, a 9 mm thick gauge, a 8 mm
thick gauge, a 7 mm thick gauge, a 6 mm thick gauge, or a 5 mm
thick gauge, or anywhere in between.
[0087] In certain other embodiments, the aluminum alloy product can
be hot rolled to a gauge greater than 15 mm thick (i.e., a plate).
For example, the aluminum alloy product can be hot rolled to a 25
mm thick gauge, a 24 mm thick gauge, a 23 mm thick gauge, a 22 mm
thick gauge, a 21 mm thick gauge, a 20 mm thick gauge, a 19 mm
thick gauge, a 18 mm thick gauge, a 17 mm thick gauge, or a 16 mm
thick gauge, or any suitable gauge in between or above 25 mm
thick.
[0088] In other cases, the aluminum alloy product can be hot rolled
to a gauge no more than 4 mm (i.e., a sheet). In some embodiments,
the aluminum alloy product is hot rolled to a 1 mm to 4 mm thick
gauge, which is referred to as a sheet. For example, the aluminum
alloy product can be hot rolled to a 4 mm thick gauge, a 3 mm thick
gauge, a 2 mm thick gauge, or a 1 mm thick gauge, or anywhere in
between.
Cold Rolling and Annealing and Further Rolling
[0089] Following the hot rolling, one or more cold rolling passes
may be performed. In certain embodiments, the rolled product from
the hot rolling step (e.g., the plate, shate, or sheet) can be cold
rolled to a thin gauge shate or sheet. In some embodiments, this
thin-gauge shate or sheet is cold rolled to have a thickness (i.e.,
a first thickness) ranging from 1.0 mm to 12.0 mm, or from 2.0 mm
to 8.0 mm, or from 3.0 mm to 6.0 mm, or from 4.0 mm to 5.0 mm. In
some embodiments, this thin-gauge shate or sheet is cold rolled to
have a thickness 12.0 mm, 11.9 mm, 11.8 mm, 11.7 mm, 11.6 mm, 11.5
mm, 11.4 mm, 11.3 mm, 11.2 mm, 11.1 mm, 11.0 mm, 10.9 mm, 10.8 mm,
10.7 mm, 10.6 mm, 10.5 mm, 10.4 mm, 10.3 mm, 10.2 mm, 10.1 mm, 10.0
mm, 9.9 mm, 9.8 mm, 9.7 mm, 9.6 mm, 9.5 mm, 9.4 mm, 9.3 mm, 9.2 mm,
9.1 mm, 9.0 mm, 8.9 mm, 8.8 mm, 8.7 mm, 8.6 mm, 8.5 mm, 8.4 mm, 8.3
mm, 8.2 mm, 8.1 mm, 8.0 mm, 7.9 mm, 7.8 mm, 7.7 mm, 7.6 mm, 7.5 mm,
7.4 mm, 7.3 mm, 7.2 mm, 7.1 mm, 7.0 mm, 6.9 mm, 6.8 mm, 6.7 mm, 6.6
mm, 6.5 mm, 6.4 mm, 6.3 mm, 6.2 mm, 6.1 mm, 6.0 mm, 5.9 mm, 5.8 mm,
5.7 mm, 5.6 mm, 5.5 mm, 5.4 mm, 5.3 mm, 5.2 mm, 5.1 mm, 5.0 mm, 4.9
mm, 4.8 mm, 4.7 mm, 4.6 mm, 4.5 mm, 4.4 mm, 4.3 mm, 4.2 mm, 4.1 mm,
4.0 mm, 3.9 mm, 3.8 mm, 3.7 mm, 3.6 mm, 3.5 mm, 3.4 mm, 3.3 mm, 3.2
mm, 3.1 mm, 3.0 mm, 2.9 mm, 2.8 mm, 2.7 mm, 2.6 mm, 2.5 mm, 2.4 mm,
2.3 mm, 2.2 mm, 2.1 mm, 2.0 mm, 1.9 mm, 1.8 mm, 1.7 mm, 1.6 mm, 1.5
mm, 1.4 mm, 1.3 mm, 1.2 mm, 1.1 mm, or 1.0 mm, or anywhere in
between.
[0090] In some embodiments, the one or more cold rolling passes
reduce the thickness of rolled aluminum product by at least 30%, or
at least 35%, or at least 40%, or at least 45%, or at least 50%, or
at least 55%, or at least 60%, or at least 65%, or at least 70%. In
some embodiments, the one or more cold rolling passes reduce the
cast product to a thickness (i.e., a first thickness) of no more
than 10 mm, or no more than 9 mm, or no more than 8 mm, or no more
than 7 mm, or no more than 6 mm, or no more than 5 mm.
[0091] Following one or more cold rolling passes, annealing may be
performed. This can also be referred to as an intermediate
annealing or inter-annealing, as it is performed in the middle of
the rolling process, as, in some embodiments, one or more
additional rolling passes are carried out after the annealing.
[0092] The annealing step can include heating the rolled aluminum
product from room temperature to a temperature from 380.degree. C.
to 500.degree. C. (e.g., from 385.degree. C. to 495.degree. C.,
from 390.degree. C. to 490.degree. C., from 395.degree. C. to
485.degree. C., from 400.degree. C. to 480.degree. C., from
405.degree. C. to 475.degree. C., from 410.degree. C. to
470.degree. C., from 415.degree. C. to 465.degree. C., from
420.degree. C. to 460.degree. C., from 425.degree. C. to
455.degree. C., from 430.degree. C. to 460.degree. C., from
380.degree. C. to 450.degree. C., from 405.degree. C. to
475.degree. C., or from 430.degree. C. to 500.degree. C.).
[0093] This intermediate annealing step can, for example, lead to
certain beneficial texture features in the resulting article. In
particular, the intermediate annealing assists in the formation of
the recrystallized microstructure on surface of the article and the
recovered and/or unrecrystallized structure in the middle of the
article. In some examples, the texture on surface of the article
will be dominated by recrystallization components, including cube,
cube_ND, and cube_RD, rather than deformation type components, such
as Bs, S, and Cu. Therefore, the bending performance of the article
is improved without reducing the strength.
[0094] The plate, shate, or sheet can soak at the intermediate
annealing temperature for a period of time. In one non-limiting
example, the plate, shate, or sheet is allowed to soak for up to
approximately 2 hours (e.g., from about 15 to about 120 minutes,
inclusively). For example, the plate, shate, or sheet can be soaked
at the temperature of from about 400.degree. C. to about
500.degree. C. for 15 minutes, 20 minutes, 25 minutes, 30 minutes,
35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60
minutes, 65 minutes, 70 minutes, 75 minutes, 80 minutes, 85
minutes, 90 minutes, 95 minutes, 100 minutes, 105 minutes, 110
minutes, 115 minutes, or 120 minutes, or anywhere in between.
[0095] In some embodiments, the intermediate annealing of the
rolled aluminum alloy product is carried out at a temperature of no
more than 45.degree. C., or no more than 40.degree. C., or no more
than 35.degree. C., or no more than 30.degree. C., or no more than
25.degree. C., or no more than 20.degree. C., or no more than
15.degree. C., or no more than 10.degree. C., above the minimum
recrystallization temperature of the aluminum alloy. In some
embodiments, the intermediate annealing of the rolled aluminum
alloy product is carried out at a temperature above the minimum
recrystallization temperature of the aluminum alloy for no more
than 3.0 hours, or no more than 2.5 hours, or no more than 2.0
hours, or no more than 1.5 hours, or no more than 1.0 hours.
[0096] Optionally, the intermediate annealing may comprise multiple
annealing sub-steps. For example, in some embodiments, the
annealing is carried out at a first temperature above the minimum
recrystallization temperature for a first period of time and at a
second temperature above the minimum recrystallization temperature
for a second period of time. For example, the first temperature
above the minimum recrystallization temperature may be greater than
the second temperature above the minimum recrystallization
temperature. Annealing may, for example, subject the surface
portions to higher temperature annealing conditions at earlier
times than the intermediate portion. By using a two (or more) step
intermediate annealing process in which the temperature at the
second step is lower than that at the first step, the surface
portions of the rolled aluminum alloy product may be subjected to
recrystallization conditions for longer periods of time than the
intermediate portion. This may also occur in a single step
intermediate annealing process in which a single annealing
temperature is used, but the effect may be more pronounced in a
multiple step annealing process.
[0097] Optionally, following the intermediate annealing, further
rolling is performed, such as cold rolling. In some embodiments,
one or more additional cold rolling passes are performed. This
additional rolling brings the aluminum alloy product to a final
thickness (i.e., a second thickness). In some embodiments, the
final thickness ranges from 0.1 mm to 4.0 mm. In some embodiments,
the final thickness is 4.0 mm, 3.9 mm, 3.8 mm, 3.7 mm, 3.6 mm, 3.5
mm, 3.4 mm, 3.3 mm, 3.2 mm, 3.1 mm, 3.0 mm, 2.9 mm, 2.8 mm, 2.7 mm,
2.6 mm, 2.5 mm, 2.4 mm, 2.3 mm, 2.2 mm, 2.1 mm, 2.0 mm, 1.9 mm, 1.8
mm, 1.7 mm, 1.6 mm, 1.5 mm, 1.4 mm, 1.3 mm, 1.2 mm, 1.1 mm, 1.0 mm,
0.9 mm, 0.8 mm, 0.7 mm, 0.6 mm, 0.5 mm, 0.4 mm, 0.3 mm, 0.2 mm, or
0.1 mm. In some further such embodiments, the final thickness is no
more than 4.0 mm, or no more than 3.5 mm, or no more than 3.0 mm,
or no more than 2.5 mm, or no more than 2.0 mm, or no more than 1.5
mm, or no more than 1.0 mm, or no more than 0.5 mm, or no more than
0.3 mm, or no more than 0.1 mm.
Finishing Steps
[0098] Optionally, following the intermediate annealing and/or the
additional rolling, additional finishing steps can be carried out,
including, but not limited to, one or more of solutionizing,
quenching, ageing, and coiling.
[0099] In some embodiments, a solution heat treatment step can be
carried out. The solution heat treatment step can include heating
the aluminum alloy product from room temperature to a temperature
of from 430.degree. C. to 500.degree. C. For example, the solution
heat treatment step can include heating the aluminum alloy product
from room temperature to a temperature of from 440.degree. C. to
500.degree. C., from 460.degree. C. to 500.degree. C., or from
480.degree. C. to 490.degree. C. In some examples, the heating rate
for the solution heat treatment step can be from 250.degree.
C./hour to 350.degree. C./hour (e.g., 250.degree. C./hour,
255.degree. C./hour, 260.degree. C./hour, 265.degree. C./hour,
270.degree. C./hour, 275.degree. C./hour, 280.degree. C./hour,
285.degree. C./hour, 290.degree. C./hour, 295.degree. C./hour,
300.degree. C./hour, 305.degree. C./hour, 310.degree. C./hour,
315.degree. C./hour, 320.degree. C./hour, 325.degree. C./hour,
330.degree. C./hour, 335.degree. C./hour, 340.degree. C./hour,
345.degree. C./hour, or 350.degree. C./hour).
[0100] In some embodiments, the aluminum alloy product can then be
cooled to a temperature of about 25.degree. C. at a quench speed
that can vary between about 50.degree. C./s to 400.degree. C./s in
a quenching step that is based on the selected gauge. For example,
the quench rate can be from about 50.degree. C./s to about
375.degree. C./s, from about 60.degree. C./s to about 375.degree.
C./s, from about 70.degree. C./s to about 350.degree. C./s, from
about 80.degree. C./s to about 325.degree. C./s, from about
90.degree. C./s to about 300.degree. C./s, from about 100.degree.
C./s to about 275.degree. C./s, from about 125.degree. C./s to
about 250.degree. C./s, from about 150.degree. C./s to about
225.degree. C./s, or from about 175.degree. C./s to about
200.degree. C./s.
[0101] In the quenching step, the aluminum alloy product is rapidly
quenched with a liquid (e.g., water) and/or gas or another selected
quench medium. In certain aspects, the aluminum alloy product can
be rapidly quenched with water. In certain embodiments, the
aluminum alloy product is quenched with air.
[0102] In some embodiments, the aluminum alloy product can be
artificially aged for a period of time to result in the T6 or T7
temper. In certain embodiments, the aluminum alloy product can be
artificially aged (AA) at about 100.degree. C. to 225.degree. C.
(e.g., 100.degree. C., 105.degree. C., 110.degree. C., 115.degree.
C., 120.degree. C., 125.degree. C., 130.degree. C., 135.degree. C.,
140.degree. C., 145.degree. C., 150.degree. C., 155.degree. C.,
160.degree. C., 165.degree. C., 170.degree. C., 175.degree. C.,
180.degree. C., 185.degree. C., 190.degree. C., 195.degree. C.,
200.degree. C., 205.degree. C., 210.degree. C., 215.degree. C.,
220.degree. C., or 225.degree. C.) for a period of time.
Optionally, the aluminum alloy product can be cold worked and
artificially aged for a period from about 15 minutes to about 48
hours (e.g., 15 minutes, 30 minutes, 1 hour, 2 hours, 3 hours, 4
hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11
hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours,
18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24
hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, 30 hours,
31 hours, 32 hours, 33 hours, 34 hours, 35 hours, 36 hours, 37
hours, 38 hours, 39 hours, 40 hours, 41 hours, 42 hours, 43 hours,
44 hours, 45 hours, 46 hours, 47 hours, or 48 hours, or anywhere in
between).
[0103] In some embodiments, an annealing step during or after
production can also be applied to produce the aluminum alloy
product in a coil form for improved productivity or formability.
For example, an alloy in coil form can be supplied in the O temper,
using a hot or cold rolling step and an annealing step following
the hot or cold rolling step. Forming may occur in O temper, which
is followed by solution heat treatment, quenching and artificial
aging/paint baking.
[0104] In certain aspects, to produce an aluminum alloy product in
coil form and with high formability compared to F temper, an
annealing step can be applied to the coil. Without intending to
limit the invention, the purpose for the annealing and the
annealing parameters may include (1) releasing the work-hardening
in the material to gain formability; (2) recrystallizing or
recovering the material without causing significant grain growth;
(3) engineering or converting texture to be appropriate for forming
and for reducing anisotropy during formability; and (4) avoiding
the coarsening of pre-existing precipitation particles.
[0105] In one or more aspects, the disclosure provides aluminum
alloy articles formed by the processes set forth above, or any
embodiments thereof.
Articles of Manufacture
[0106] The disclosure provides an article of manufacture, which is
comprised of an aluminum alloy product disclosed herein. In some
embodiments, the article of manufacture is comprised of a rolled
aluminum alloy product. Examples of such articles of manufacture
include, but are not limited to, an automobile, a truck, a trailer,
a train, a railroad car, an airplane, a body panel or part for any
of the foregoing, a bridge, a pipeline, a pipe, a tubing, a boat, a
ship, a storage container, a storage tank, a an article of
furniture, a window, a door, a railing, a functional or decorative
architectural piece, a pipe railing, an electrical component, a
conduit, a beverage container, a food container, or a foil.
[0107] In some other embodiments, the aluminum alloy articles
disclosed herein can be used in automotive and/or transportation
applications, including motor vehicle, aircraft, and railway
applications, or any other desired application. In some examples,
the aluminum alloy products disclosed herein can be used to prepare
motor vehicle body part products, such as bumpers, side beams, roof
beams, cross beams, pillar reinforcements (e.g., A-pillars,
B-pillars, and C-pillars), inner panels, outer panels, side panels,
inner hoods, outer hoods, or trunk lid panels. The aluminum alloys
and methods described herein can also be used in aircraft or
railway vehicle applications, to prepare, for example, external and
internal panels.
[0108] In some other embodiments, the aluminum alloy articles
disclosed herein can be used in electronics applications. For
example, the aluminum alloy products disclosed herein can also be
used to prepare housings for electronic devices, including mobile
phones and tablet computers. In some examples, the alloys can be
used to prepare housings for the outer casing of mobile phones
(e.g., smart phones) and tablet bottom chassis.
[0109] In some other embodiments, the aluminum alloy articles
disclosed herein can be used in industrial applications. For
example, the aluminum alloy products disclosed herein can be used
to prepare products for the general distribution market.
[0110] In some other embodiments, the aluminum alloy articles
disclosed herein can be used as aerospace body parts. For example,
the aluminum alloy articles disclosed herein can be used to prepare
structural aerospace body parts, such as a wing, a fuselage, an
aileron, a rudder, an elevator, a cowling, or a support. In some
other embodiments, the aluminum alloy articles disclosed herein can
be used to prepare non-structural aerospace body parts, such as a
seat track, a seat frame, a panel, or a hinge.
[0111] The following examples serve to further illustrate certain
embodiments of the present disclosure without, at the same time,
however, constituting any limitation thereof. On the contrary, it
is to be clearly understood that resort may be had to various
embodiments, modifications and equivalents thereof which, after
reading the description herein, may suggest themselves to those of
ordinary skill in the art without departing from the spirit of the
disclosure.
Example 1--Alloy Compositions
[0112] Six aluminum alloys (A1/Alloy A1, A2/Alloy A2, A3/Alloy A3,
A4/Alloy A4, A5/Alloy A5, and A6/Alloy A6) were prepared, whose
elemental composition is set forth in Table 3 below. The elemental
compositions are provided in weight percentages.
TABLE-US-00003 TABLE 3 Alloy Cr Cu Fe Ga Mg Mn Ni Si Ti V Zn Zr Al
A1 0.03 1.13 0.18 0.01 2.25 0.03 0.003 0.10 0.05 0.01 7.92 0.14
bal. A2 0.10 1.12 0.18 0.01 2.24 0.04 0.003 0.09 0.05 0.01 7.86
0.14 bal. A3 0.04 1.70 0.19 0.01 2.56 0.05 0.003 0.10 0.04 0.01
5.51 0.14 bal. A4 0.04 1.77 0.20 0.01 2.67 0.04 0.003 0.08 0.04
0.01 5.38 0.14 bal. A5 0.03 1.24 0.19 0.010 2.31 0.03 0.003 0.08
0.05 0.01 7.64 0.13 bal. A6 0.24 1.63 0.17 n/a 2.75 0.02 n/a 0.04
0.02 n/a 5.94 0.001 bal. All expressed in wt. %. n/a = not present
or present in trace quantities (<0.0005 wt. %)
Example 2--Manufacture of Aluminum Alloy Sheet
[0113] The test aluminum alloy sheets with chemical composition
corresponding to Alloys A1-A6 from Table 3 (Example 1), were cast
by Direct Chill (DC) casting. All were stress relieved and
homogenized, and subsequently hot-rolled to a hot band having a
gauge of 10.5 mm. Each was then subjected to cold rolling. For
each, the hot band went through 2 passes of cold rolling from 10.5
mm to 6 mm and 4 mm, respectively.
[0114] Inter-annealing of Alloys A1, A2 and A3 was performed at 4.0
mm gauge, with a 50.degree. C./hr ramping rate to 410.degree. C.,
soaked for 60 minutes, then furnace cooled to 350.degree. C. and
soaked for 1200 minutes. The coils were allowed to cool to room
temperature in air. A final cold rolling was then performed on
these three samples, Alloys A1, A2, and A3. The coils were cold
rolled to final gauge of 2.0 mm with 1 pass.
[0115] For Alloys A4, A5, and A6, the hot band of 10.5 mm gauge was
cold rolled to 6.0 mm, then to 4.0 mm, then to 2.8 mm, and then to
2.0 mm, without any inter-annealing steps.
[0116] Solution heat treatment of test blanks of samples of Alloys
A1-A6 were carried out, where the samples were heated up using a
furnace to a PMT of 480.degree. C. and soaked for 5 minutes, before
being taken out of the furnace and quenched in warm water at
55.degree. C. at a quench rate of around 350.degree. C./sec.
Artificial aging of samples of Alloys A1-A6 was carried out using a
furnace at 125.degree. C. and soaked for 24 hours to bring the
samples to T6 temper.
Example 3--Optical Microscopy and Scanning Electron Micrographs
with EBSD
[0117] Optical microscopy (OM) was carried out for aluminum alloy
sheets made of the alloys of Example 1, such as according to
Example 2. FIG. 2 shows an optical micrograph (OM) of a
cross-section of a sample of Alloy A1 that was lab rolled with
inter-annealing, and which shows recovered and/or unrecrystallized
microstructure through the thickness of the sample. FIG. 3A shows
an optical micrograph (OM) of a cross-section of a sample of Alloy
A1 that was plant rolled with inter-annealing. The sample of Alloy
A1 of FIG. 3A includes a first surface portion 205, an intermediate
portion 210, and a second surface portion 215.
[0118] "Plant Rolled" samples were cold-rolled according to
standard plant cold rolling processes. "Lab Rolled" samples were
cold-rolled in a laboratory setting from 10.5 mm to 2.0 mm by
conducting 17 different passes, each of which reduced the thickness
by about 0.5 mm.
[0119] FIG. 3B shows a surface portion from FIG. 3A, showing
recrystallized microstructure, corresponding to at least a portion
of first surface portion 205 or second surface portion 215. In FIG.
3B, the grain structure of the sample can be seen, with individual
grains not spread significantly in the surface portion, indicating
that the crystal structure has been recovered and/or is
unrecrystallized by the inter-annealing process. FIG. 3C shows nine
modified reduced-size versions of FIG. 3B, generated by reducing
FIG. 3B to 9 individual colors in order to highlight various colors
shown in FIG. 3B as black. For example, in panel 1, dark purple
features of FIG. 3B are depicted in black. In panel 2, light purple
features of FIG. 3B are depicted in black. In panel 3, black
features of FIG. 3B are depicted in black. In panel 4, light blue
features of FIG. 3B are depicted in black. In panel 5, dark blue
features of FIG. 3B are depicted in black. In panel 6, orange
features of FIG. 3B are depicted in black. In panel 7, medium blue
features of FIG. 3B are depicted in black. In panel 8, yellow
features of FIG. 3B are depicted in black. In panel 9, pink
features of FIG. 3B are depicted in black.
[0120] FIG. 3D shows a center section from FIG. 3A, showing
recovered and/or unrecrystallized microstructure, corresponding to
at least a portion of intermediate portion 210. In FIG. 3D, the
remnants of grains that were significantly spread during the
initial rolling process can be seen. The remnants do not all
recrystallize during the inter-annealing process and many regions
remain spread in the center portion, reflecting the recovered
and/or unrecrystallized nature of the intermediate portion 210.
FIG. 3E shows nine modified reduced-size versions of FIG. 3D,
generated by reducing FIG. 3D to 9 individual colors in order to
highlight various colors shown in FIG. 3D as black. For example, in
panel 1, dark purple features of FIG. 3D are depicted in black. In
panel 2, light purple features of FIG. 3D are depicted in black. In
panel 3, black features of FIG. 3D are depicted in black. In panel
4, light blue features of FIG. 3D are depicted in black. In panel
5, dark blue features of FIG. 3D are depicted in black. In panel 6,
orange features of FIG. 3D are depicted in black. In panel 7,
medium blue features of FIG. 3D are depicted in black. In panel 8,
yellow features of FIG. 3D. are depicted in black. In panel 9, pink
features of FIG. 3D. are depicted in black.
[0121] FIG. 4A shows an optical micrograph of a sample of Alloy A5
that was plant rolled without inter-annealing during the cold
rolling process, showing spread grains as horizontal structures in
FIG. 4A. FIG. 4B shows a section from the center portion in FIG. 4A
corresponding to at least a portion of the intermediate portion,
showing recovered and/or unrecrystallized microstructure. FIG. 4C
shows a surface portion from FIG. 4A, showing recrystallized
microstructure.
[0122] Electron backscattering diffraction (EBSD) disorientation
mapping was carried out on certain samples. Mapping of a
cross-section of samples of Alloy A1 that were rolled to a final
gauge and finished with a T6 temper is shown in FIGS. 5A, 5B, and
5C. The low angle boundaries (2-15) are marked as darker-color
horizontal lines, while the medium to high angle boundaries
(>15) are marked as lighter-color horizontal lines. FIG. 5A
provides mapping for an Alloy A1 sample that was lab rolled,
without inter-annealing during the cold rolling process, which has
a uniform microstructure with recovered and/or unrecrystallized
microstructure through the whole thickness, while FIG. 5B provides
mapping for an Alloy A1 sample that was plant rolled, with
inter-annealing during the cold rolling process, which shows the
recrystallization microstructure near the surface and recovered
and/or unrecrystallized microstructure in the center (i.e.,
intermediate portion). FIG. 5C shows mapping for an Alloy A5 sample
that was plant rolled, without inter-annealing during the cold
rolling process, which has a microstructure between that shown in
FIG. 5A and FIG. 5B. Quantitative results from these images are
presented in Table 4 below.
Example 4--Recrystallization Quotient
[0123] The recrystallization quotient (RQ) was calculated using the
EBSD measurements described in Example 3. Orientation mapping was
performed on a square grid across a cross-sectionally cut area. The
mapped area was divided into three equally sized areas spanning the
thickness of the sheet, and the recrystallization quotient was
calculated for each area. Table 4 reports the values of the
recrystallization quotient for each of the samples described in
Example 3. The "Surface RQ" refers to RQ for the two surface areas
(i.e., surface portions), "Center RQ" refers to the RQ for the
center area (i.e., intermediate portion), and the "Overall RQ"
refers to the RQ across the thickness of the entire sample. Note
that "IA" refers to inter-annealing performed during the cold
rolling process.
TABLE-US-00004 TABLE 4 Overall Surface Center Sample RQ RQ RQ Alloy
A1, Lab Processed 0.512 0.532 0.467 Alloy A1, Plant Rolled without
IA 0.684 0.819 0.553 Alloy A5, Plant Rolled with IA 0.758 0.871
0.592
[0124] The "Plant Rolled" samples were cold-rolled according to
standard plant cold rolling processes. The "Lab Rolled" sample was
cold-rolled in a laboratory setting from 10.5 mm to 2.0 mm by
conducting 17 different passes, each of which reduced the thickness
by about 0.5 mm.
Example 5--Bending
[0125] The bendability was measured for samples of aluminum alloy
sheets prepared according to Example 2. The bendability for the
samples was measured according to Spec VDA-238-100. The samples
were tested in the longitudinal and transverse directions in T6
temper. FIG. 6 shows the 3-point bend results of Alloys A1, A2, A5
(without IA) and a sample of AA7075 sheet. The angle reported was
.beta. angle, thus the lower the better. For Alloys A1 and A2, the
left bar is for the longitudinal direction and the right bar is for
the transverse direction. For Alloys A5 and the AA7076 sample, only
the longitudinal direction is shown. All were tested in the T6
temper.
Example 6--Exfoliation Corrosion
[0126] The exfoliation corrosion (EXCO) was measured for certain
aluminum alloy sheets prepared according to Example 2. The EXCO was
measured according to the procedure set forth in ASTM-G34, which
involved the continuous immersion of test materials in a solution
containing 4 M sodium chloride, 0.5 M potassium nitrate, and 0.1 M
nitric acid at 25.+-.3.degree. C. The susceptibility to exfoliation
was determined by visual examination, with performance ratings
established by reference to standard photographs (see the G34 test
procedure). Visual examination was conducted, along with
longitudinal cross-section metallographic examination. FIGS. 7A-7E
show photographs of tested aluminum alloy sheets, as identified in
Table 5 below.
TABLE-US-00005 TABLE 5 Sample FIG. No. Alloy A1, Plant Processed
without IA 7A Alloy A2, Plant Processed without IA 7B Alloy A6,
Plant Processed without IA 7C Alloy A1, Lab Processed with IA 7D
Alloy A2, Lab Processed with IA 7E
Example 7--Yield Strength
[0127] The yield strength was measured for certain aluminum alloy
sheets prepared according to Example 2. The yield strength was
tested in accordance to ASTM E8 with 2'' standard gauge length.
FIG. 8 shows the results of yield strength testing on certain
samples, where L, T, and D stand for longitudinal, transverse and
diagonal, respectively, with respect to rolling direction. For
Alloy A1, Alloy A2, Alloy A3, and Alloy A6, the three bars show the
results of testing in the longitudinal, transverse, and diagonal
directions, respectively, from left to right. For Alloy A5, the two
bars show the results of testing in the longitudinal and transverse
directions, respectively, from left to right.
Illustrations
[0128] As used below, any reference to a series of illustrations is
to be understood as a reference to each of those examples
disjunctively.
[0129] Illustration 1 is an aluminum alloy article, which is
comprised of an aluminum alloy material and further comprises a
first surface portion; a second surface portion opposing the first
surface portion; and an intermediate portion between the first
surface portion and the second surface portion; wherein the first
surface portion comprises a rolled surface and the second surface
portion comprises a rolled surface; and wherein the aluminum alloy
material of the first surface portion and the second surface
portion have a higher recrystallization quotient than the aluminum
alloy material of the intermediate portion.
[0130] Illustration 2 is the aluminum alloy article of any
preceding or subsequent illustration, wherein the aluminum alloy
material is a 5xxx series aluminum alloy, a 6xxx series aluminum
alloy, or a 7xxx series aluminum alloy.
[0131] Illustration 3 is the aluminum alloy article of any
preceding or subsequent illustration, wherein the aluminum alloy
material is a 7xxx series aluminum alloy.
[0132] Illustration 4 is the aluminum alloy material of any
preceding or subsequent illustration, wherein the aluminum alloy
material is an aluminum alloy selected from the group consisting of
AA7011, AA7019, AA7020, AA7021, AA7039, AA7072, AA7075, AA7085,
AA7108, AA7108A, AA7015, AA7017, AA7018, AA7019A, AA7024, AA7025,
AA7028, AA7030, AA7031, AA7033, AA7035, AA7035A, AA7046, AA7046A,
AA7003, AA7004, AA7005, AA7009, AA7010, AA7011, AA7012, AA7014,
AA7016, AA7116, AA7122, AA7023, AA7026, AA7029, AA7129, AA7229,
AA7032, AA7033, AA7034, AA7036, AA7136, AA7037, AA7040, AA7140,
AA7041, AA7049, AA7049A, AA7149,7204, AA7249, AA7349, AA7449,
AA7050, AA7050A, AA7150, AA7250, AA7055, AA7155, AA7255, AA7056,
AA7060, AA7064, AA7065, AA7068, AA7168, AA7175, AA7475, AA7076,
AA7178, AA7278, AA7278A, AA7081, AA7181, AA7185, AA7090, AA7093,
AA7095, and AA7099.
[0133] Illustration 5 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the aluminum
alloy material comprises: from 4.0 to 15.0 percent by weight Zn;
from 0.1 to 3.5 wt. % Cu; from 1.0 to 4.0 wt. % Mg; from 0.05 to
0.50 wt. % Fe; from 0.05 to 0.30 wt. % Si; from 0.01 to 0.50 wt. %
Zr; up to 0.25 wt. % Mn; up to 0.20 wt. % Cr; up to 0.15 wt. % Ti;
and up to 0.15 wt. % impurities; with the remainder being A1.
[0134] Illustration 6 is the aluminum alloy article of any
preceding or subsequent illustration, wherein the aluminum alloy
material comprises: from 5.6 to 9.3 wt. % Zn; from 0.2 to 2.6 wt. %
Cu; from 1.4 to 2.8 wt. % Mg; from 0.10 to 0.35 wt. % Fe; from 0.05
to 0.20 wt. % Si; from 0.05 to 0.25 wt. % Zr; up to 0.05 wt. % Mn;
up to 0.10 wt. % Cr; up to 0.05 wt. % Ti; and up to 0.15 wt. %
impurities; with the remainder being A1.
[0135] Illustration 7 is the aluminum alloy article of any
preceding or subsequent illustration, further comprising up to 0.10
wt. % of one or more elements selected from the group consisting of
Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, Sc, and Ni.
[0136] Illustration 8 is the aluminum alloy article of any one of
any preceding or subsequent illustration, further comprising up to
0.10 wt. % of one or more elements selected from the group
consisting of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er,
Tm, Yb, and Lu.
[0137] Illustration 9 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the rolled
surface of the first surface portion is formed by a process that
comprises cold rolling.
[0138] Illustration 10 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the rolled
surface of the second surface portion is formed by a process that
comprises cold rolling.
[0139] Illustration 11 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the aluminum
alloy article is a rolled aluminum alloy shate or a rolled aluminum
alloy sheet.
[0140] Illustration 12 is the aluminum alloy article of any
preceding or subsequent illustration, wherein the aluminum alloy
article has a thickness of no more than 15 mm, or no more than 14
mm, or no more than 13 mm, or no more than 12 mm, or no more than
11 mm, or no more than 10 mm, or no more than 9 mm, or no more than
8 mm, or no more than 7 mm, or no more than 6 mm, or no more than 5
mm, or no more than 4 mm, or no more than 3 mm, or no more than 2
mm, or no more than 1 mm, or no more than 0.5 mm, or no more than
0.3 mm, or no more than 0.1 mm.
[0141] Illustration 13 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the first surface
portion extends from the surface of the first surface portion to a
depth of no more than 40.0%, or no more than 35.0%, or no more than
33.3%, or no more than 30.0%, or no more than 25.0%, or no more
than 20.0%, or no more than 15.0%, or no more than 10.0%, of the
thickness of the aluminum alloy article.
[0142] Illustration 14 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the second
surface portion extends from the surface of the second surface
portion to a depth of no more than 40.0%, or no more than 35.0%, or
no more than 33.3%, or no more than 30.0%, or no more than 25.0%,
or no more than 20.0%, or no more than 15.0%, or no more than
10.0%, of the thickness of the aluminum alloy article.
[0143] Illustration 15 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the intermediate
portion extends from the depth of the first surface portion to the
depth of the second surface portion.
[0144] Illustration 16 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the intermediate
portion lies between the depth of the first surface portion and the
depth of the second surface portion, includes the midpoint in the
thickness between the depth of the first surface portion and the
depth of the second surface portion, and includes no more than
10.0%, or no more than 20.0%, or no more than 30.0%, or no more
than 40.0%, or no more than 50.0%, or no more than 60.0%, or no
more than 70.0%, or no more than 80.0%, or no more than 90.0%, or
no more than 95.0%, or no more than 97.0%, or no more than 99.0%,
of the thickness between the depth of the first surface portion and
the depth of the second surface portion.
[0145] Illustration 17 is the aluminum alloy article of any
preceding or subsequent illustration, wherein the midpoint in the
thickness between the depth of the first surface portion and the
depth of the second surface portion lies at midpoint in the
thickness of the intermediate portion.
[0146] Illustration 18 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the aluminum
alloy material of the second surface portion has a higher
recrystallization quotient than the aluminum alloy material of the
intermediate portion.
[0147] Illustration 19 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the aluminum
alloy material of the first surface portion has a recrystallization
quotient that is higher, such as at least 0.01 higher, or at least
0.03 higher, or at least 0.05 higher, or at least 0.07 higher, or
at least 0.10 higher, or at least 0.15 higher, or at least 0.20
higher, or at least 0.25 higher, than the recrystallization
quotient of the aluminum alloy material of the intermediate
portion.
[0148] Illustration 20 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the aluminum
alloy material of the second surface portion has a
recrystallization quotient that is higher, such as at least 0.01
higher, or at least 0.03 higher, or at least 0.05 higher, or at
least 0.07 higher, or at least 0.10 higher, or at least 0.15
higher, or at least 0.20 higher, or at least 0.25 higher, than the
recrystallization quotient of the aluminum alloy material of the
intermediate portion.
[0149] Illustration 21 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the aluminum
alloy material of the first surface portion has a recrystallization
quotient of at least 0.50, or at least 0.55, or at least 0.60, or
at least 0.65, or at least 0.70, or at least 0.75, or at least
0.80, or at least 0.85, or at least 0.90.
[0150] Illustration 22 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the aluminum
alloy material of the second surface portion has a
recrystallization quotient of at least 0.50, or at least 0.55, or
at least 0.60, or at least 0.65, or at least 0.70, or at least
0.75, or at least 0.80, or at least 0.85, or at least 0.90.
[0151] Illustration 23 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the aluminum
alloy material of the intermediate portion has a recrystallization
quotient of no more than 0.25, or no more than 0.30, or no more
than 0.35, or no more than 0.40, or no more than 0.45, or no more
than 0.50, or no more than 0.55, or no more than 0.60, or no more
than 0.65.
[0152] Illustration 24 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the aluminum
alloy article, when subjected to bendability testing according to
Specification VDA 238-100, has a .beta. angle of no more than
138.degree., or no more than 137.degree., no more than 136.degree.,
no more than 135.degree., no more than 134.degree., no more than
133.degree., no more than 132.degree., or no more than
131.degree..
[0153] Illustration 25 is the aluminum alloy article of any one of
any preceding or subsequent illustration, wherein the aluminum
alloy article, when subjected to exfoliation corrosion testing
according to ASTM Test No. G34-01, has a exfoliation corrosion
rating of EA.
[0154] Illustration 26 is a method of making an aluminum alloy
article, the method comprising providing an aluminum alloy, wherein
the aluminum alloy is provided in a molten state as a molten
aluminum alloy; casting the molten aluminum alloy to form an
aluminum alloy cast product; homogenizing the aluminum alloy cast
product to form a homogenized aluminum alloy cast product; rolling
the homogenized aluminum alloy cast product to form a first rolled
aluminum alloy product having a first thickness, wherein the
rolling comprises one or more hot rolling passes and one or more
cold rolling passes, wherein the one or more hot rolling passes
precede the one or more cold rolling passes; annealing the first
rolled aluminum alloy product at a temperature of not more than
50.degree. C. above the minimum recrystallization temperature of
the aluminum alloy to form a first annealed aluminum product; and
rolling the first annealed aluminum alloy product to form a second
rolled aluminum product having a second thickness.
[0155] Illustration 27 is the method of any preceding or subsequent
illustration, wherein the aluminum alloy is a 5xxx series aluminum
alloy, a 6xxx series aluminum alloy, or a 7xxx series aluminum
alloy.
[0156] Illustration 28 is the method of any preceding or subsequent
illustration, wherein the aluminum alloy is a 7xxx series aluminum
alloy.
[0157] Illustration 29 is the method of any preceding or subsequent
illustration any one of any preceding or subsequent illustration,
wherein the aluminum alloy comprises: from 4.0 to 15.0 wt. % Zn;
from 0.1 to 3.5 wt. % Cu; from 1.0 to 4.0 wt. % Mg; from 0.05 to
0.50 wt. % Fe; from 0.05 to 0.30 wt. % Si; from 0.05 to 0.25 wt. %
Zr; up to 0.25 wt. % Mn; up to 0.20 wt. % Cr; up to 0.15 wt. % Ti;
and up to 0.15 wt. % impurities; with the remainder being A1.
[0158] Illustration 30 is the method of any preceding or subsequent
illustration, wherein the aluminum alloy comprises: from 5.6 to 9.3
wt. % Zn; from 0.2 to 2.6 wt. % Cu; from 1.4 to 2.8 wt. % Mg; from
0.10 to 0.35 wt. % Fe; from 0.05 to 0.20 wt. % Si; from 0.05 to
0.15 wt. % Zr; up to 0.05 wt. % Mn; up to 0.10 wt. % Cr; up to 0.05
wt. % Ti; and up to 0.15 wt. % impurities; with the remainder being
A1.
[0159] Illustration 31 is the method of any preceding or subsequent
illustration, further comprising up to 0.10 wt. % of one or more
elements selected from the group consisting of Mo, Nb, Be, B, Co,
Sn, Sr, V, In, Hf, Ag, Sc, and Ni.
[0160] Illustration 32 is the method of any one of any preceding or
subsequent illustration, further comprising up to 0.10 wt. % of one
or more elements selected from the group consisting of Y, La, Ce,
Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.
[0161] Illustration 33 is the method of any one of any preceding or
subsequent illustration, wherein the casting is carried out by
direct chill (DC) casting.
[0162] Illustration 34 is the method of any one of any preceding or
subsequent illustration, wherein the casting is carried out by
continuous casting.
[0163] Illustration 35 is the method of any preceding or subsequent
illustration, wherein the casting is carried out by twin-belt
continuous casting.
[0164] Illustration 36 is the method of any one of any preceding or
subsequent illustration, wherein the one or more cold rolling
passes of the rolling used to form the first rolled aluminum alloy
product reduce the thickness of rolled aluminum product by at least
30%, or at least 35%, or at least 40%, or at least 45%, or at least
50%, or at least 55%, or at least 60%, or at least 65%, or at least
70%.
[0165] Illustration 37 is the method of any one of any preceding or
subsequent illustration, wherein the first thickness is no more
than 10 mm, or no more than 9 mm, or no more than 8 mm, or no more
than 7 mm, or no more than 6 mm, or no more than 5 mm, or no more
than 4 mm.
[0166] Illustration 38 is the method of any one of any preceding or
subsequent illustration, wherein the first thickness is from 1 mm
to 10 mm, or from 2 mm to 8 mm, or from 3 mm to 6 mm.
[0167] Illustration 39 is the method of any one of any preceding or
subsequent illustration, wherein the annealing of the first rolled
aluminum alloy product is carried out at a temperature of no more
than 45.degree. C., or no more than 40.degree. C., or no more than
35.degree. C., or no more than 30.degree. C., or no more than
25.degree. C., or no more than 20.degree. C., or no more than
15.degree. C., or no more than 10.degree. C., above the minimum
recrystallization temperature of the aluminum alloy.
[0168] Illustration 40 is the method of any one of any preceding or
subsequent illustration, wherein the annealing of the first rolled
aluminum alloy product is carried out at a temperature above the
minimum recrystallization temperature of the aluminum alloy for no
more than 3.0 hours, or no more than 2.5 hours, or no more than 2.0
hours, or no more than 1.5 hours, or no more than 1.0 hours.
[0169] Illustration 41 is the method of any one of any preceding or
subsequent illustration, wherein the second thickness is no more
than 4.0 mm, or no more than 3.5 mm, or no more than 3.0 mm, or no
more than 2.5 mm, or no more than 2.0 mm, or no more than 1.5 mm,
or no more than 1.0 mm, or no more than 0.5 mm, or no more than 0.3
mm, or no more than 0.1 mm.
[0170] Illustration 42 is the method of any one of any preceding or
subsequent illustration, further comprising treating the second
rolled aluminum alloy product to form a finished aluminum alloy
product.
[0171] Illustration 43 is the method of any preceding or subsequent
illustration, wherein the treating comprises one or more processes
selected from the group consisting of: annealing, solutionizing,
quenching, ageing, and coiling.
[0172] Illustration 44 is the method of any preceding or subsequent
illustration, wherein the finished aluminum alloy product is an
aluminum alloy sheet in the T6 or T7 temper.
[0173] Illustration 45 is an aluminum alloy article, wherein the
aluminum alloy article is the second rolled aluminum alloy product
formed by the method of any one of any preceding or subsequent
illustration.
[0174] Illustration 46 is an aluminum alloy article, wherein the
aluminum alloy article is the finished aluminum alloy product
formed by the method of any one of any preceding or subsequent
illustration.
[0175] Illustration 47 is an article of manufacture, which is
comprised of an aluminum alloy article of any one of any preceding
or subsequent illustration.
[0176] Illustration 48 is the article of manufacture of any
preceding or subsequent illustration, wherein the article of
manufacture is an automobile, a truck, a trailer, a train, a
railroad car, an airplane, a body panel or part for any of the
foregoing, a bridge, a pipeline, a pipe, a tubing, a boat, a ship,
a storage container, a storage tank, a an article of furniture, a
window, a door, a railing, a functional or decorative architectural
piece, a pipe railing, an electrical component, a conduit, a
beverage container, a food container, or a foil.
[0177] Illustration 49 is the article of manufacture of any
preceding or subsequent illustration, wherein the article of
manufacture is an automotive body part.
[0178] Illustration 50 is the article of manufacture of any
preceding or subsequent illustration, wherein the automotive body
part is a motor vehicle body part.
[0179] Illustration 51 is the article of manufacture of any
preceding or subsequent illustration, wherein the motor vehicle
body part is a bumper, a side beam, a roof beam, a cross beam, a
pillar reinforcement, an inner panel, an outer panel, a side panel,
an inner hood, an outer hood, or a trunk lid panel.
[0180] Illustration 52 is the article of manufacture of any
preceding or subsequent illustration, wherein the article of
manufacture is an electronic device housing.
[0181] Illustration 53 is the article of manufacture of any
preceding or subsequent illustration, wherein the article of
manufacture is an aerospace body part.
[0182] Illustration 54 is the article of manufacture of any
preceding or subsequent illustration, wherein the aerospace body
part is a structural body part.
[0183] Illustration 55 is the article of manufacture of any
preceding or subsequent illustration, wherein the structural body
part is a wing, a fuselage, an aileron, a rudder, an elevator, a
cowling, or a support.
[0184] Illustration 56 is the article of manufacture of any
preceding or subsequent illustration, wherein the aerospace body
part is a non-structural body part.
[0185] Illustration 57 is the article of manufacture of any
preceding or subsequent illustration, wherein the non-structural
body part is a seat track, a seat frame, a panel, or a hinge.
[0186] Illustration 58 is a method of making an aluminum alloy
article, the method comprising: casting an aluminum alloy to form
an aluminum alloy cast product; homogenizing the aluminum alloy
cast product to form a homogenized aluminum alloy cast product;
subjecting the homogenized aluminum alloy cast product to a first
rolling process to form a first rolled aluminum alloy product
having a first thickness, wherein the first rolling process
comprises one or more hot rolling passes followed by one or more
cold rolling passes; annealing the first rolled aluminum alloy
product at a temperature of not more than 50.degree. C. above a
minimum recrystallization temperature of the aluminum alloy to form
a first annealed aluminum product; and subjecting the first
annealed aluminum alloy product to a second rolling process to form
a second rolled aluminum alloy product having a second
thickness.
[0187] Illustration 59 is the method of any preceding or subsequent
illustration, wherein the aluminum alloy is a 5xxx series aluminum
alloy, a 6xxx series aluminum alloy, or a 7xxx series aluminum
alloy.
[0188] Illustration 60 is the method of any preceding or subsequent
illustration, wherein the first thickness is no more than 10
mm.
[0189] Illustration 61 is the method of any preceding or subsequent
illustration, wherein the annealing is carried out at the
temperature above the minimum recrystallization temperature for no
more than 3.0 hours.
[0190] Illustration 62 is the method of any preceding or subsequent
illustration, wherein the annealing is carried out at a first
temperature above the minimum recrystallization temperature for a
first period of time and at a second temperature above the minimum
recrystallization temperature for a second period of time, wherein
the first temperature above the minimum recrystallization
temperature is greater than the second temperature above the
minimum recrystallization temperature.
[0191] Illustration 63 is the method of any preceding or subsequent
illustration, wherein the second thickness is no more than 4.0
mm.
[0192] Illustration 64 is the method of any preceding or subsequent
illustration, wherein the second rolled aluminum alloy product
comprises: a first surface portion, wherein the first surface
portion comprises a first rolled surface, and wherein the first
surface portion has a first recrystallization quotient; a second
surface portion opposing or opposite the first surface portion,
wherein the second surface portion comprises a second rolled
surface, and wherein the second surface portion has a second
recrystallization quotient; and an intermediate portion positioned
between the first surface portion and the second surface portion,
wherein the intermediate portion has a third recrystallization
quotient, and wherein the third recrystallization quotient is less
than the first recrystallization quotient or the second
recrystallization quotient or both.
[0193] Illustration 65 is the method of any preceding or subsequent
illustration, wherein the first recrystallization quotient is
between 0.50 and 1.0, wherein the second recrystallization quotient
is between 0.50 and 1.0, or wherein the third recrystallization
quotient is between 0.01 and 0.65.
[0194] Illustration 66 is an aluminum alloy article comprising an
aluminum alloy material, the aluminum alloy material comprising: a
first surface portion, wherein the first surface portion comprises
a first rolled surface, and wherein the first surface portion has a
first recrystallization quotient; a second surface portion opposing
or opposite the first surface portion, wherein the second surface
portion comprises a second rolled surface, and wherein the second
surface portion has a second recrystallization quotient; and an
intermediate portion positioned between the first surface portion
and the second surface portion, wherein the intermediate portion
has a third recrystallization quotient, and wherein the third
recrystallization quotient is less than the first recrystallization
quotient or the second recrystallization quotient or both.
[0195] Illustration 67 is the aluminum alloy article of any
preceding or subsequent illustration, wherein the aluminum alloy
material is a 5xxx series aluminum alloy, a 6xxx series aluminum
alloy, or a 7xxx series aluminum alloy.
[0196] Illustration 68 is the aluminum alloy article of any
preceding or subsequent illustration, wherein one or both of the
first rolled surface or the second rolled surface is formed by a
process that comprises cold rolling.
[0197] Illustration 69 is the aluminum alloy article of any
preceding or subsequent illustration, wherein the first surface
portion extends from a surface of the first surface portion to
first a depth of no more than 40.0% of a thickness of the aluminum
alloy article.
[0198] Illustration 70 is the aluminum alloy article of any
preceding or subsequent illustration, wherein the second surface
portion extends from a surface of the second surface portion to a
second depth of no more than 40.0% of the thickness of the aluminum
alloy article.
[0199] Illustration 71 is the aluminum alloy article of any
preceding or subsequent illustration, wherein the intermediate
portion extends from a first depth of the first surface portion to
a second depth of the second surface portion.
[0200] Illustration 72 is the aluminum alloy article of any
preceding or subsequent illustration, wherein the first surface
portion has a first recrystallization quotient, wherein the second
surface portion has a second recrystallization quotient, wherein
the intermediate portion has a third recrystallization quotient,
and wherein the third recrystallization quotient is less than the
first recrystallization quotient or the second recrystallization
quotient or both.
[0201] Illustration 73 is the aluminum alloy article of any
preceding or subsequent illustration, wherein the first
recrystallization quotient is at least 0.50, wherein the second
recrystallization quotient is at least 0.50, or wherein the third
recrystallization quotient is no more than 0.65.
[0202] Illustration 74 is the aluminum alloy article of any
preceding or subsequent illustration, having a .beta. angle of
between 100.degree. and 138.degree. for bendability testing
according to Specification VDA 238-100.
[0203] Illustration 75 is the aluminum alloy article of any
preceding or subsequent illustration, having an exfoliation
corrosion rating of EA for exfoliation corrosion testing according
to ASTM Test No. G34-01.
[0204] Illustration 76 is the aluminum alloy article of any
preceding illustration, wherein a recrystallization quotient
corresponds to a percentage or fractional amount, volume, or mass
of a portion of an aluminum alloy material, such as a surface
portion or intermediate portion, that is recrystallized as compared
to a total amount, volume, or mass of the portion of the aluminum
alloy material.
[0205] All patents, patent applications, publications, and
abstracts cited above are incorporated herein by reference in their
entirety. Various embodiments of the invention have been described
in fulfillment of the various objectives of the invention. It
should be recognized that these embodiments are merely illustrative
of the principles of the present invention. Numerous modifications
and adaptations thereof will be readily apparent to those of
ordinary skill in the art without departing from the spirit and
scope of the invention as defined in the following claims.
* * * * *