U.S. patent application number 17/344711 was filed with the patent office on 2021-12-16 for high strength recycled aluminum alloys from manufacturing scrap with cosmetic appeal.
The applicant listed for this patent is Apple Inc.. Invention is credited to Brian M. Gable, Herng-Jeng Jou, Katie L. Sassaman.
Application Number | 20210388468 17/344711 |
Document ID | / |
Family ID | 1000005695051 |
Filed Date | 2021-12-16 |
United States Patent
Application |
20210388468 |
Kind Code |
A1 |
Jou; Herng-Jeng ; et
al. |
December 16, 2021 |
HIGH STRENGTH RECYCLED ALUMINUM ALLOYS FROM MANUFACTURING SCRAP
WITH COSMETIC APPEAL
Abstract
The disclosure provides an aluminum alloy including iron (Fe) in
an amount of 0.10 wt % to 0.50 wt %; silicon (Si) in an amount of
0.50 wt % to 1.00 wt %; magnesium (Mg) in amount of 0.50 wt % to
0.90 wt %; one of manganese (Mn) or chromium (Cr) in amount from
0.040 to 0.500 wt %; additional non-aluminum (Al) elements in an
amount not exceed 3.5 wt %; and the remaining wt % being Al and
incidental impurities, wherein the alloy has a Mg/Si ratio of equal
to or greater than 0.90.
Inventors: |
Jou; Herng-Jeng; (San Jose,
CA) ; Gable; Brian M.; (San Jose, CA) ;
Sassaman; Katie L.; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Apple Inc. |
Cupertino |
CA |
US |
|
|
Family ID: |
1000005695051 |
Appl. No.: |
17/344711 |
Filed: |
June 10, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
63123856 |
Dec 10, 2020 |
|
|
|
63038261 |
Jun 12, 2020 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B21B 3/00 20130101; B21B
2003/001 20130101; B21C 23/002 20130101; C22C 21/08 20130101 |
International
Class: |
C22C 21/08 20060101
C22C021/08; B21C 23/00 20060101 B21C023/00; B21B 3/00 20060101
B21B003/00 |
Claims
1. An aluminum alloy comprising: iron (Fe) in an amount of 0.10 wt
% to 0.50 wt %; silicon (Si) in an amount of 0.50 wt % to 1.00 wt
%; magnesium (Mg) in amount of 0.50 wt % to 0.90 wt %; one of
manganese (Mn) or chromium (Cr) in amount from 0.030 to 0.500 wt %
Cr in an amount from 0.030 to 0.500 wt %, or a combination of Mn
and Cr in an amount from 0.030 to 0.800 wt %; additional
non-aluminum (Al) elements in an amount not exceeding 3.5 wt %; and
the remaining wt % being Al and incidental impurities, wherein the
alloy has a Mg/Si ratio of equal to or greater than 0.90.
2. The aluminum alloy of claim 1, comprising manganese (Mn) in an
amount from 0.040 to 0.500 wt %, Cr in an amount from 0.040 to
0.500 wt %, or a combination of Mn and Cr in an amount from 0.040
to 0.800 wt %.
3. The aluminum alloy of claim 1, wherein a combination of Mn and
Cr is in an amount of 0.040 wt % to 0.800 wt %.
4. The alloy of claim 1, wherein the Mg/Si ratio is equal to or
greater than 1.00.
5. The alloy of claim 1, further comprising titanium (Ti) from 0 to
0.10 wt %.
6. The alloy of claim 1, wherein manganese (Mn) is from 0.090 to
0.110 wt %.
7. The alloy of any claim 1, further comprising non-aluminum
elements selected from: copper (Cu) from 0.010 to 0.050 wt %;
chromium (Cr) from 0.040 to 0.100 wt %; zinc (Zn) from 0 to 0.20 wt
%; gallium (Ga) from 0 to 0.20 wt %; tin (Sn) from 0 to 0.20 wt %;
vanadium (V) from 0 to 0.20 wt %; calcium (Ca) from 0 to 0.001 wt
%; sodium (Na) from 0 to 0.002 wt %; boron (B) from 0 to 0.01 wt %;
zirconium (Zr) from 0 to 0.01 wt %; lithium (Li) from 0 to 0.01 wt
%; cadmium (Cd) from 0 to 0.01 wt %; lead (Pb) from 0 to 0.01 wt %;
nickel (Ni) from 0 to 0.01 wt %; phosphorous (P) from 0 to 0.01 wt
%; and combinations thereof.
8. The alloy of claim 1, wherein the alloy has an elongation less
than or equal to 16%.
9. The alloy of claim 1, wherein the alloy has a yield strength of
at least 270 MPa and a tensile strength of at least 310 MPa.
10. The aluminum alloy of claim 9, wherein the additional
non-aluminum elements in an amount do not exceed 1.0 wt %, and
wherein the aluminum alloy has a yield strength of at least 300 MPa
and a tensile strength of 330 MPa.
11. The aluminum alloy of claim 1, wherein the alloy comprises
.alpha.-AlFe(Mn)Si particles of an average diameter of 5 .mu.m.
12. (canceled)
13. A process for recycling manufacturing scrap, the process
comprising: (a) obtaining an aluminum alloy according to claim 1
from manufacturing scrap, (b) melting the aluminum alloy to form a
melted aluminum alloy; (c) casting the melted aluminum alloy to
form a casted alloy; (d) extruding or rolling the casted alloy to
form an extrusion or a sheet; and (e) fabricating the extrusion or
the sheet to produce a product.
14. (canceled)
15. (canceled)
16. (canceled)
17. (canceled)
18. (canceled)
19. (canceled)
20. The process of claim 13, wherein the alloy has an extrusion
speed of at least 20% higher than 7000 series alloys.
21. The process of claim 13, wherein the step of melting comprises
removing oxides from the aluminum alloys.
22. (canceled)
23. An aluminum alloy comprising: iron (Fe) in an amount of 0.10 wt
% to 0.50 wt %; silicon (Si) in an amount of 0.50 wt % to 1.00 wt
%; magnesium (Mg) in amount of 0.50 wt % to 0.90 wt %; manganese
(Mn) in amount from 0 to 0.30 wt %; additional non-aluminum (Al)
elements in an amount not exceed 3.0 wt %; and the remaining wt %
being Al and incidental impurities, wherein the alloy has a Mg/Si
ratio of less than or equal to 1.0.
24. The alloy of claim 23, wherein the Mg/Si ratio is less than or
equal to 0.90.
25. The alloy of claim 23, further comprising titanium (Ti) from 0
to 0.10 wt %.
26. The alloy of claim 23, wherein manganese (Mn) is from 0.005 to
0.25 wt %.
27. The alloy of claim 23, further comprising non-aluminum elements
selected from: copper (Cu) from 0.010 to 0.050 wt %; chromium (Cr)
from 0 to 0.10 wt %; zinc (Zn) from 0 to 0.20 wt %; gallium (Ga)
from 0 to 0.20 wt %; tin (Sn) from 0 to 0.20 wt %; vanadium (V)
from 0 to 0.20 wt %; calcium (Ca) from 0 to 0.001 wt %; sodium (Na)
from 0 to 0.002 wt %; boron (B) from 0 to 0.01 wt %; zirconium (Zr)
from 0 to 0.01 wt %; lithium (Li) from 0 to 0.01 wt %; cadmium (Cd)
from 0 to 0.01 wt %; lead (Pb) from 0 to 0.01 wt %; nickel (Ni)
from 0 to 0.01 wt %; phosphorous (P) from 0 to 0.01 wt %; and
combinations thereof.
28. The alloy of claim 23, wherein the alloy has an average grain
size less than or equal to 130 .mu.m and a grain aspect ratio
between 0.8 and 1.3.
29. The alloy of claim 23, wherein the alloy has an elongation less
than or equal to 14%.
30. The alloy of claim 23, wherein the alloy has a yield strength
of at least 250 MPa and a tensile strength of at least 280 MPa.
31. The aluminum alloy of claim 30, wherein the additional
non-aluminum elements in an amount do not exceed 1.0 wt %, and
wherein the aluminum alloy has a yield strength of at least 270 MPa
and a tensile strength of 300 MPa.
32. (canceled)
33. A process for recycling manufacturing scrap, the process
comprising: (a) obtaining an aluminum alloy according to claim 23
from manufacturing scrap, (b) melting the aluminum alloy to form a
melted aluminum alloy; (c) casting the melted aluminum alloy to
form a casted alloy; (d) extruding or rolling the casted alloy to
form an extrusion or a sheet; and (e) fabricating the extrusion or
the sheet to produce a product.
34. (canceled)
35. (canceled)
36. (canceled)
37. (canceled)
38. (canceled)
39. (canceled)
40. (canceled)
41. The process of claim 32, wherein the alloy has an extrusion
speed of at least 20% higher than 7000 series alloys.
42. The process of claim 32, wherein the step of melting comprises
removing oxides from the aluminum alloys.
Description
PRIORITY
[0001] This patent application claims the benefit of U.S.
Provisional Patent Application No. 63/038,261, entitled "High
Strength Recycled Aluminum Alloys from Manufactured Scrap with
Cosmetic Appeal," filed on Jun. 12, 2020, and U.S. Provisional
Patent Application No. 63/123,856 entitled "Aluminum Alloys with
High Strength and Cosmetic Appeal," filed Dec. 10, 2020, both of
which are incorporated herein by reference in their entirety.
FIELD
[0002] The disclosure is directed to high strength recycled
aluminum alloys and processes for recycling aluminum alloy scrap
with cosmetic appeal and applications including enclosures for
electronic devices.
BACKGROUND
[0003] Commercial aluminum alloys, such as the 6063 aluminum (Al)
alloys, have been used for fabricating enclosures for electronic
devices. Cosmetic appeal is very important for enclosures for
electronic devices.
[0004] Conventional recycling of manufacturing chip scrap (e.g.
6063 Al) is generally associated with downgraded quality.
Sometimes, in order to maintain the quality of the recycled
product, conventional recycling of manufacturing chip scrap and may
be limited to a particular source and a limited amount of scrap in
the recycled material.
[0005] There remains a need for developing alloys and processes for
recycling manufacturing scrap to improve the strength and cosmetic
appeal of the recycled aluminum alloys.
BRIEF SUMMARY
[0006] In one aspect, the disclosure provides an aluminum alloy
including iron (Fe) in an amount of 0.10 wt % to 0.50 wt %; silicon
(Si) in an amount of 0.50 wt % to 1.00 wt %; magnesium (Mg) in
amount of 0.50 wt % to 0.90 wt %; one of manganese (Mn) or chromium
(Cr) in amount from 0.040 to 0.500 wt %; additional non-aluminum
(Al) elements in an amount not exceed 3.5 wt %; and the remaining
wt % being Al and incidental impurities, wherein the alloy has a
Mg/Si ratio of equal to or greater than 0.90.
[0007] In another aspect, a process is provided for recycling
manufacturing scrap. The process may include (a) obtaining an
aluminum alloy from manufacturing scrap. The aluminum alloy may
include iron (Fe) in an amount of 0.10 wt % to 0.50 wt %; silicon
(Si) in an amount of 0.50 wt % to 1.00 wt %; magnesium (Mg) in
amount of 0.50 wt % to 0.90 wt %; one of manganese (Mn) or chromium
(Cr) in amount from 0.04 to 0.50 wt %; additional non-aluminum (Al)
elements in an amount not exceeding 3.5 wt %; and the remaining wt
% being Al and incidental impurities. The alloy may have a Mg/Si
ratio of equal to or greater than 0.90. The alloy may have a yield
strength of at least 250 MPa and a tensile strength of at least 280
MPa. The process may also include (b) melting the aluminum alloy to
form a melted aluminum alloy; (c) casting the melted aluminum alloy
to form a casted alloy; (d) extruding or rolling the casted alloy
to form an extrusion or a sheet; and (e) fabricating the extrusion
or the sheet to produce a product.
[0008] In another aspect, the disclosure provides an aluminum alloy
including iron (Fe) in an amount of 0.10 wt % to 0.50 wt %, silicon
(Si) in an amount of 0.50 wt % to 1.00 wt %, magnesium (Mg) in
amount of 0.50 wt % to 0.90 wt %, manganese (Mn) in amount of 0 to
0.30 wt %, non-aluminum (Al) elements in an amount not exceeding
3.0 wt %, the remaining wt % being Al and incidental impurities.
The alloy may have a Mg/Si ratio of less than or equal to 1.0.
[0009] In another aspect, a process is provided for recycling
manufacturing scrap. The process may include (a) obtaining an
aluminum alloy from manufacturing scrap; (b) melting the aluminum
alloy to form a melted aluminum alloy; (c) casting the melted
aluminum alloy to form a casted alloy; (d) extruding or rolling the
casted alloy to form an extrusion or a sheet; and (e) fabricating
the extrusion or sheet to produce a product.
[0010] Additional embodiments and features are set forth in part in
the description that follows, and will become apparent to those
skilled in the art upon examination of the specification or may be
learned by the practice of the disclosed subject matter. A further
understanding of the nature and advantages of the disclosure may be
realized by reference to the remaining portions of the
specification and the drawings, which forms a part of this
disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The description will be more fully understood with reference
to the following figures and data graphs, which are presented as
various embodiments of the disclosure and should not be construed
as a complete recitation of the scope of the disclosure,
wherein:
[0012] FIG. 1 depicts a recycling process from materials including
manufacturing scrap in accordance with embodiments of the
disclosure;
[0013] FIG. 2 depicts a flow chart for a recycling process from
scrap in accordance with embodiments of the disclosure;
[0014] FIG. 3 shows Si versus Mg compositions for various aluminum
alloys in accordance with embodiments of the disclosure;
[0015] FIG. 4 shows Si versus Mg compositions for Alloys 1-11 in
accordance with embodiments of the disclosure;
[0016] FIG. 5 illustrates higher extrusion speed for Alloys 3 and 7
than 7000 series alloys (e.g. Reference Alloy 3) in accordance with
embodiments of the disclosure.
[0017] FIG. 6 illustrates the yield strength for extrusion samples
formed of Alloys 3 and 7 in accordance with embodiments of the
disclosure;
[0018] FIG. 7 illustrates the tensile strength for extrusion
samples formed of Alloys 3 and 7 in accordance with embodiments of
the disclosure;
[0019] FIG. 8 illustrates the elongation for extrusion samples
formed of Alloys 3 and 7 in accordance with embodiments of the
disclosure;
[0020] FIG. 9 illustrates the average grain size for extrusion
samples formed of Alloys 3 and 7 in accordance with embodiments of
the disclosure;
[0021] FIG. 10 illustrates the largest grain size for extrusion
samples formed of Alloys 3 and 7 in accordance with embodiments of
the disclosure;
[0022] FIG. 11 illustrates the grain aspect ratio for extrusion
samples formed of Alloys 3 and 7 in accordance with embodiments of
the disclosure;
[0023] FIG. 12 illustrates yield strengths, elongation, and
anodization color b* for Alloys 2, 3, 5, 6, and 7 in accordance
with embodiments of the disclosure;
[0024] FIG. 13 shows the comparison of yield strengths of various
aluminum alloys in accordance with embodiments of the
disclosure;
[0025] FIG. 14 illustrates yield strengths for extrusion samples
formed of Alloys 1 and 7-11 in accordance with embodiments of the
disclosure;
[0026] FIG. 15 illustrates tensile strengths for extrusion samples
formed of Alloys 1 and 7-11 in accordance with embodiments of the
disclosure;
[0027] FIG. 16 illustrates elongations for extrusion samples formed
of Alloys 1 and 7-11 in accordance with embodiments of the
disclosure;
[0028] FIG. 17 illustrates anodization color b* change (.DELTA.b*)
relative to Alloy 7 for alloys 8-11 in accordance with embodiments
of the disclosure;
[0029] FIG. 18 illustrates average diameters for Alloys 1 and 7-11
in accordance with embodiments of the disclosure;
[0030] FIG. 19 illustrates a SEM image of the microstructure of
Alloy 7 in accordance with embodiments of the disclosure;
[0031] FIG. 20 illustrates a SEM image of the microstructure of
Alloy 10 in accordance with embodiments of the disclosure; and
[0032] FIG. 21 illustrates a SEM image of the microstructure of
Alloy 9 after extrusion in accordance with embodiments of the
disclosure.
DETAILED DESCRIPTION
[0033] The disclosure may be understood by reference to the
following detailed description, taken in conjunction with the
drawings as described below. It is noted that, for purposes of
illustrative clarity, certain elements in various drawings may not
be drawn to scale.
Overview
[0034] Reference Alloy 1 was a representative 6000 series alloy
disclosed in U.S. patent application Ser. No. 16/530,830, entitled
"Recycled Aluminum Alloys from Manufacturing Scrap with Cosmetic
Appeal," by Gable et al., filed on Aug. 2, 2019, which is
incorporated by reference in its entirety. Reference Alloy 1 has
similar strength as a virgin aluminum alloy 6063, which is referred
to Reference Alloy 2 in the disclosure. The Reference Alloy 1 can
provide the same or similar cosmetic appeal, mechanical properties,
and microstructure as the virgin or primary aluminum alloy. The
Reference Alloy 1 can include higher Fe content, and/or higher Si
content than aluminum alloys made from primary aluminum.
[0035] This disclosure provides a recycled 6000 series aluminum
alloys that utilizes manufacturing scraps for cosmetic application.
The disclosed recycled aluminum alloys can achieve 30% higher
tensile yield strength than Reference Alloy 1, while still
achieving reasonable anodization cosmetics and without difficulty
in manufacturing processes (e.g. extrusion process). Also,
incorporation of 100% recycling of manufacturing scraps in
Reference Alloy 1 was maintained in the disclosed alloy.
[0036] The disclosed recycled 6000 series aluminum alloys were also
formed from scrap. The scrap can be collected from manufacturing
processes of conventional aluminum alloys (e.g. 6000 series
aluminum alloys or 6063 aluminum). The disclosed alloy can include
higher Mn content, higher Si content, and higher Mg content than
Reference Alloy 1.
[0037] The disclosure also provides Mn, Mg, and Si compositions to
achieve properties including aspects of microstructure, color,
strengths, ductility, and processability. For example, an addition
of a small amount of Mn (e.g. 0.040 to 0.500 wt %) surprisingly
provides increased conversion of large .beta.-AlFeSi particles to
small .alpha.-AlFeSi particles, and increased the yield strengths,
tensile strengths, and elongations of alloys. Increasing Mn (e.g.
0.040 to 0.500 wt %) was also found to increase anodization color
b* of the alloys. Also, increasing Mg increased the yield strengths
and tensile strengths of alloys and also reduce anodization color
b* of the alloys. However, increasing Mg (e.g. 0.1 wt %) can also
make extrusion more difficult. Further, increasing Si (e.g. 0.2 wt
%) increased the yield strengths and tensile strengths of alloys.
Increasing Si was also found to reduce the ductility. Decreasing Si
lowered the anodization color b* of the alloys. Decreasing Si also
promotes the formation of small .alpha.-AlFeSi particles.
[0038] For the higher strength applications where a 7000 series
aluminum alloy (e.g. Reference Alloy 3) was considered for possible
uses, there was concern for the corrosion resistance of the 7000
series aluminum alloy. Reference Alloy 3 was a representative alloy
disclosed in U.S. patent Ser. No. 15/406,153, entitled "ALUMINUM
ALLOYS WITH HIGH STRENGTH AND COSMETIC APPEAL," by Misra et al.,
issued on Jan. 13, 2017, which is incorporated by reference in its
entirety. The disclosed alloys can provide an alternative to reduce
the risk of corrosion of the 7000 series aluminum alloys. The
disclosed alloy can be used for an electronic enclosure. The
disclosed alloy has demonstrated 30% higher tensile yield strength
than Reference Alloy 1. The disclosed alloy also revealed
comparable yield strength with the 7000 series aluminum alloys, and
promising microstructure and ano cosmetics. Also, the disclosed
alloy revealed reasonable extrudability and was extruded at 60%
higher speed than 7000 series aluminum alloys.
Alloys Formed of Manufacturing Scrap
[0039] In some variations, the disclosed 6000 series aluminum
alloys are designed to be tolerant to include up to 100% recycled
6000 series aluminum, such as casting scrap, extrusion scrap, chip
scrap from manufacturing, among others. The disclosed 6000 series
aluminum alloys may also be tolerant to other series scraps, such
as 1000 series scrap. The disclosed 6000 series aluminum alloys
allow a closed-loop of manufacturing scrap that can reduce use of
virgin aluminum, and result in significant reduction of emissions
and related carbon footprint. Conventional 6000 series Al can
include small amounts of Si and Mg, and optionally includes small
amounts of Fe, Mn, Cu, Zr, Pb, Cr, Zn, among others.
[0040] FIG. 1 depicts an example of a recycling process from
materials including manufacturing scrap in accordance with
embodiments of the disclosure. As shown in FIG. 1, a primary
aluminum 102 is supplied to material processing 104. Material
processing 104 may use recycled materials that incorporates scrap
from module manufacturing 106, to build chips. Then, module
manufacturing 106 uses the chips fabricated from material
processing 104 to build modules. The module manufacturing 106 may
have process fallout 110, which provides scrap to material
processing 104. This process can be a closed-loop. The disclosure
provides materials and methods for recycling scrap from module
manufacturing 106.
[0041] A customer 114 uses the modules from the module
manufacturing 106 to build product, which may be used in field in
operation 112. A recovered material 108 may be produced from the
field used product. The recovered material 108 may also be provided
to material processing 104.
[0042] Recycled aluminum alloys can accumulate more iron than is
typically present in virgin aluminum alloys. The increase in iron
can have a negative effect on the cosmetic appeal of aluminum
alloys, particularly by having a more gray color. Iron cannot be
removed from aluminum alloys by conventional industrial methods,
and once iron is included in the aluminum alloy, the amount of iron
in the alloy cannot be reduced. Because of the number of
iron-containing contact points in a typical supply chain, the
amount of iron can be higher in recycled aluminum than in virgin
aluminum.
[0043] Iron can have negative effects on the cosmetic appeal by
creating an unattractive gray color. In addition to having a
negative effect on cosmetics, iron contributes to the formation of
iron-aluminum-silicon particles during processing. The acquisition
of Si by the iron-containing particles reduces the amount of Si
available for strengthening. As such, more Si is added to the
alloys disclosed herein. The presently disclosed alloys have
increased silicon and increased iron. Contrary to expectations,
various properties of the alloy are consistent or better than
alloys with such undesirable amounts of iron.
[0044] The disclosed recycled 6000 series aluminum alloys allow use
of recycled materials, such as manufacturing scrap from various
sources. The disclosed recycled 6000 series aluminum alloys result
in significant reduction of the carbon footprint associated with
manufacturing.
[0045] The alloys can be described by various wt % of elements, as
well as specific properties. In all descriptions of the alloys
described herein, it will be understood that the wt % balance of
alloys is Al and incidental impurities. Impurities can be present,
for example, as a byproduct of processing and manufacturing. In
various embodiments, an incidental impurity can be no greater than
0.05 wt % of any one additional element (i.e., a single impurity),
and no greater than 0.10 wt % total of all additional elements
(i.e., total impurities). The impurities can be less than or equal
to about 0.1 wt %, alternatively less than or equal about 0.05 wt
%, alternatively less than or equal about 0.01 wt %, alternatively
less than or equal about 0.001 wt %.
[0046] In some variations, the alloy has at least 0.14 wt % Fe.
Further, in some variations, the alloy has at least 0.50 wt % Si
and at least 0.50 wt % Mg. In still further variations, the alloy
can have equal to or less than 0.20 wt % Fe. The alloy can have
equal to or less than 0.90 wt % Mg and equal to or less than 1.00
wt % Si.
Fe Content
[0047] As described above, the scrap (e.g., chip scrap) includes
more Fe than Reference Alloy 2. The Fe may be from sources
including tooling among others. The disclosed 6000 series aluminum
alloy is designed to have more Fe than Reference Alloy 2 or virgin
aluminum alloys currently used for cosmetic consumer electronic
products.
[0048] In some variations, iron may range from 0.10 wt % to 0.50 wt
%.
[0049] In some variations, iron may be equal to or greater than
0.10 wt %. In some variations, iron may be equal to or greater than
0.14 wt %. In some variations, iron may be equal to or greater than
0.15 wt %. In some variations, iron may be equal to or greater than
0.16 wt %. In some variations, iron may be equal to or greater than
0.17 wt %. In some variations, iron may be equal to or greater than
0.18 wt %. In some variations, iron may be equal to or greater than
0.19 wt %. In some variations, iron may be equal to or greater than
0.20 wt %. In some variations, iron may be equal to or greater than
0.25 wt %. In some variations, iron may be equal to or greater than
0.30 wt %. In some variations, iron may be equal to or greater than
0.35 wt %. In some variations, iron may be equal to or greater than
0.40 wt %. In some variations, iron may be equal to or greater than
0.45 wt %.
[0050] In some variations, iron may be equal to or less than 0.50
wt %. In some variations, iron may be equal to or less than 0.45 wt
%. In some variations, iron may be equal to or less than 0.35 wt %.
In some variations, iron may be equal to or less than 0.40 wt %. In
some variations, iron may be equal to or less than 0.35 wt %. In
some variations, iron may be equal to or less than 0.30 wt %. In
some variations, iron may be equal to or less than 0.25 wt %. In
some variations, iron may be equal to or less than 0.20 wt %. In
some variations, iron may be equal to or less than 0.19 wt %. In
some variations, iron may be equal to or less than 0.18 wt %. In
some variations, iron may be equal to or less than 0.17 wt %. In
some variations, iron may be equal to or less than 0.16 wt %. In
some variations, iron may be equal to or less than 0.15 wt %.
Ti Content
[0051] Scrap can include more Ti than the conventional 6000 series
aluminum alloys. The Ti can be added as a grain refiner during
casting process. In many instances, the 6000 series aluminum alloy
is designed to tolerate more Ti versus conventional aluminum alloys
used for similar products.
[0052] In some variations, titanium may equal to or less than 0.10
wt %. In some variations, titanium may equal to or less than 0.09
wt %. In some variations, titanium may equal to or less than 0.08
wt %. In some variations, titanium may equal to or less than 0.07
wt %. In some variations, titanium may equal to or less than 0.06
wt %. In some variations, titanium may equal to or less than 0.05
wt %. In some variations, titanium may equal to or less than 0.04
wt %. In some variations, titanium may equal to or less than 0.03
wt %. In some variations, titanium may equal to or less than 0.025
wt %. In some variations, titanium may be equal to or less than
0.020 wt %. In some variations, titanium may be equal to or less
than 0.015 wt %. In some variations, titanium may be equal to or
less than 0.010 wt %. In some variations, titanium may be equal to
or less than 0.005 wt %.
Si Content
[0053] Comparing to Reference Alloy 1 and Reference Alloy 2, the
alloy is more Si rich and forms more precipitates Mg.sub.xSi.sub.y,
which provides the alloy with higher strength. However, the
Mg.sub.xSi.sub.y precipitates also potentially affect cosmetic
appeal and color due to the formation of surface features. Reducing
Si reduces the color b* of the anodized alloy.
[0054] In some variations, silicon may vary from 0.50 wt % to 1.00
wt %.
[0055] In some variations, silicon may be equal to or less than
1.00 wt %. In some variations, silicon may be equal to or less than
0.95 wt %. In some variations, silicon may be equal to or less than
0.90 wt %. In some variations, silicon may be equal to or less than
0.85 wt %. In some variations, silicon may be equal to or less than
0.80 wt %. In some variations, silicon may be equal to or less than
0.75 wt %. In some variations, silicon may be equal to or less than
0.70 wt %. In some variations, silicon may be equal to or less than
0.65 wt %. In some variations, silicon may be equal to or less than
0.60 wt %. In some variations, silicon may be equal to or less than
0.55 wt %.
[0056] In some variations, silicon may be equal to or greater than
0.50 wt %. In some variations, silicon may be equal to or greater
than 0.55 wt %. In some variations, silicon may be equal to or
greater than 0.60 wt %. In some variations, silicon may be equal to
or greater than 0.65 wt %. In some variations, silicon may be equal
to or greater than 0.70 wt %. In some variations, silicon may be
equal to or greater than 0.75 wt %. In some variations, silicon may
be equal to or greater than 0.80 wt %. In some variations, silicon
may be equal to or greater than 0.85 wt %. In some variations,
silicon may be equal to or greater than 0.90 wt %. In some
variations, silicon may be equal to or greater than 0.95 wt %.
Mg Content and Mg/Si Ratio
[0057] Mg can be designed to have the proper Mg/Si ratio to form
Mg--Si precipitates for strengthening purpose. However, higher Mg
content can make extrusion harder. Increasing Mg reduces color b*
of the anodized alloy.
[0058] In some variations, magnesium may vary from 0.50 wt % to
0.95 wt %.
[0059] In some variations, magnesium may be equal to or less than
0.95 wt %. In some variations, magnesium may be equal to or less
than 0.90 wt %. In some variations, magnesium may be equal to or
less than 0.85 wt %, In some variations, magnesium may be equal to
or less than 0.80 wt %. In some variations, magnesium may be equal
to or less than 0.75 wt %. In some variations, magnesium may be
equal to or less than 0.70 wt %. In some variations, magnesium may
be equal to or less than 0.65 wt %. In some variations, magnesium
may be equal to or less than 0.60 wt %. In some variations,
magnesium may be equal to or less than 0.55 wt %. In some
variations, magnesium may be equal to or greater than 0.50 wt %. In
some variations, magnesium may be equal to or greater than 0.55 wt
%. In some variations, magnesium may be equal to or greater than
0.60 wt %. In some variations, magnesium may be equal to or greater
than 0.65 wt %. In some variations, magnesium may be equal to or
greater than 0.70 wt %. In some variations, magnesium may be equal
to or greater than 0.75 wt %. In some variations, magnesium may be
equal to or greater than 0.85 wt %. In some variations, magnesium
may be equal to or greater than 0.90 wt %.
[0060] The alloy 6063 or Reference Alloy 2 includes a typical
precipitate of Mg.sub.2Si, which would require a Si/Mg ratio of 0.8
or Mg/Si ratio of 1.25. The Reference Alloy 1 has a Mg/Si ratio
greater than 1. However, the disclosed alloy can have a Mg/Si ratio
lower than the Mg/Si ratio of Reference Alloy 1, and forms various
precipitates Mg.sub.xSi.sub.y.
[0061] In some variations, the ratio of Mg to Si (Mg/Si) varies
from 0.60 to 1.8.
[0062] In some variations, the ratio of Mg to Si may be equal to or
greater than 0.60. In some variations, the ratio of Mg to Si may be
equal to or greater than 0.65. In some variations, the ratio of Mg
to Si may be equal to or greater than 0.70. In some variations, the
ratio of Mg to Si may be equal to or greater than 0.75. In some
variations, the ratio of Mg to Si may be equal to or greater than
0.80. In some variations, the ratio of Mg to Si may be equal to or
greater than 0.85. In some variations, the ratio of Mg to Si may be
equal to or greater than 0.90. In some variations, the ratio of Mg
to Si may be equal to or greater than 0.95. In some variations, the
ratio of Mg to Si may be equal to or greater than 1.00. In some
variations, the ratio of Mg to Si may be equal to or greater than
1.05. In some variations, the ratio of Mg to Si may be equal to or
greater than 1.10. In some variations, the ratio of Mg to Si may be
equal to or greater than 1.15. In some variations, the ratio of Mg
to Si may be equal to or greater than 1.20. In some variations, the
ratio of Mg to Si may be equal to or greater than 1.25. In some
variations, the ratio of Mg to Si may be equal to or greater than
1.30. In some variations, the ratio of Mg to Si may be equal to or
greater than 1.40. In some variations, the ratio of Mg to Si may be
equal to or greater than 1.50. In some variations, the ratio of Mg
to Si may be equal to or greater than 1.70.
[0063] In some variations, the ratio of Mg to Si may be less than
or equal to 0.65. In some variations, the ratio of Mg to Si may be
less than or equal to 0.70. In some variations, the ratio of Mg to
Si may be less than or equal to 0.75. In some variations, the ratio
of Mg to Si may be less than or equal to 0.80. In some variations,
the ratio of Mg to Si may be less than or equal to 0.85. In some
variations, the ratio of Mg to Si may be less than or equal to
0.90. In some variations, the ratio of Mg to Si may be less than or
equal to 0.95. In some variations, the ratio of Mg to Si may be
less than or equal to 1.00. In some variations, the ratio of Mg to
Si may be less than or equal to 1.05. In some variations, the ratio
of Mg to Si may be less than or equal to 1.10. In some variations,
the ratio of Mg to Si may be less than or equal to 1.15. In some
variations, the ratio of Mg to Si may be less than or equal to
1.20. In some variations, the ratio of Mg to Si may be less than or
equal to 1.25. In some variations, the ratio of Mg to Si may be
less than or equal to 1.30. In some variations, the ratio of Mg to
Si may be less than or equal to 1.40. In some variations, the ratio
of Mg to Si may be less than or equal to 1.50. In some variations,
the ratio of Mg to Si may be less than or equal to 1.60. In some
variations, the ratio of Mg to Si may be less than or equal to
1.70. In some variations, the ratio of Mg to Si may be less than or
equal to 1.80.
Mn Content
[0064] In some variations, the alloy can include Mn. Without
wishing to be held to a particular mechanism, effect, or mode of
action, Mn can help break up the coarse Al--Fe--Si particles or
AlFeSi particles that form during casting. Mn can be added to break
up large contaminant Al--Fe--Si particles and to form smaller
Al--Fe--Si particles. The large Al--Fe--Si particles are also
referred to .beta.-AlFeSi particles, while the smaller Al--Fe--Si
and Al--Fe--Mn--Si particles are also referred to
.alpha.-AlFe(Mn)Si particles. Increasing Mn (e.g. 0.040 to 0.500 wt
%) was also found to increase anodization color b* value with
addition of Mn.
[0065] In some variations, manganese may be equal to or less than
0.500 wt %. In some variations, manganese may be equal to or less
than 0.450 wt %. In some variations, manganese may be equal to or
less than 0.400 wt %. In some variations, manganese may be equal to
or less than 0.350 wt %. In some variations, manganese may be equal
to or less than 0.300 wt %. In some variations, manganese may be
equal to or less than 0.250 wt %. In some variations, manganese may
be equal to or less than 0.200 wt %. In some variations, manganese
may be equal to or less than 0.190 wt %. In some variations,
manganese may be equal to or less than 0.180 wt %. In some
variations, manganese may be equal to or less than 0.170 wt %. In
some variations, manganese may be equal to or less than 0.160 wt %.
In some variations, manganese may be equal to or less than 0.150 wt
%. In some variations, manganese may be equal to or less than 0.140
wt %. In some variations, manganese may be equal to or less than
0.130 wt %. In some variations, manganese may be equal to or less
than 0.120 wt %. In some variations, manganese may be equal to or
less than 0.110 wt %. In some variations, manganese may be equal to
or less than 0.100 wt %. In some variations, manganese may be equal
to or less than 0.095 wt %. In some variations, manganese may be
equal to or less than 0.090 wt %. In some variations, manganese may
be equal to or less than 0.050 wt %. In some variations, manganese
may be equal to or less than 0.010 wt %. In some variations,
manganese may be equal to or less than 0.005 wt %.
[0066] In some variations, manganese may be equal to or greater
than 0 wt %. In some variations, manganese may be equal to or
greater than 0.005 wt %. In some variations, manganese may be equal
to or greater than 0.010 wt %. In some variations, manganese may be
equal to or greater than 0.040 wt %. In some variations, manganese
may be equal to or greater than 0.050 wt %. In some variations,
manganese may be equal to or greater than 0.090 wt %. In some
variations, manganese may be equal to or greater than 0.095 wt %.
In some variations, manganese may be equal to or greater than 0.100
wt %. In some variations, manganese may be equal to or greater than
0.110 wt %. In some variations, manganese may be equal to or
greater than 0.120 wt %. In some variations, manganese may be equal
to or greater than 0.130 wt %. In some variations, manganese may be
equal to or greater than 0.140 wt %. In some variations, manganese
may be equal to or greater than 0.150 wt %. In some variations,
manganese may be equal to or greater than 0.160 wt %. In some
variations, manganese may be equal to or greater than 0.170 wt %.
In some variations, manganese may be equal to or greater than 0.180
wt %. In some variations, manganese may be equal to or greater than
0.190 wt %. In some variations, manganese may be equal to or
greater than 0.200 wt %. In some variations, manganese may be equal
to or greater than 0.250 wt %. In some variations, manganese may be
equal to or greater than 0.300 wt %. In some variations, manganese
may be equal to or greater than 0.350 wt %. In some variations,
manganese may be equal to or greater than 0.400 wt %. In some
variations, manganese may be equal to or greater than 0.450 wt
%.
Cr Content
[0067] Chromium may have similar function to Mn. In some
embodiment, the alloy may include Cr in an amount of 0.040 wt % to
0.500 wt % to replace Mn. In some embodiment, the alloy may have a
combination of Mn and Cr in an amount of 0.040 wt % to 0.800 wt
%.
[0068] In some embodiments, a combination of Mn and Cr may be equal
to or less than 0.800 wt %. In some embodiments, a combination of
Mn and Cr may be equal to or less than 0.750 wt %. In some
embodiments, a combination of Mn and Cr may be equal to or less
than 0.700 wt %. In some embodiments, a combination of Mn and Cr
may be equal to or less than 0.650 wt %. In some embodiments, a
combination of Mn and Cr may be equal to or less than 0.600 wt %.
In some embodiments, a combination of Mn and Cr may be equal to or
less than 0.550 wt %. In some embodiments, a combination of Mn and
Cr may be equal to or less than 0.500 wt %. In some embodiments, a
combination of Mn and Cr may be equal to or less than 0.450 wt %.
In some embodiments, a combination of Mn and Cr may be equal to or
less than 0.400 wt %. In some embodiments, a combination of Mn and
Cr may be equal to or less than 0.350 wt %. In some embodiments, a
combination of Mn and Cr may be equal to or less than 0.300 wt %.
In some embodiments, a combination of Mn and Cr may be equal to or
less than 0.250 wt %. In some embodiments, a combination of Mn and
Cr may be equal to or less than 0.200 wt %. In some embodiments, a
combination of Mn and Cr may be equal to or less than 0.150 wt %.
In some embodiments, a combination of Mn and Cr may be equal to or
less than 0.100 wt %. In some embodiments, a combination of Mn and
Cr may be equal to or less than 0.050 wt %.
[0069] In some embodiments, a combination of Mn and Cr may be equal
to or greater than 0.750 wt %. In some embodiments, a combination
of Mn and Cr may be equal to or greater than 0.700 wt %. In some
embodiments, a combination of Mn and Cr may be equal to or greater
than 0.650 wt %. In some embodiments, a combination of Mn and Cr
may be equal to or greater than 0.600 wt %. In some embodiments, a
combination of Mn and Cr may be equal to or greater than 0.550 wt
%. In some embodiments, a combination of Mn and Cr may be equal to
or greater than 0.500 wt %. In some embodiments, a combination of
Mn and Cr may be equal to or greater than 0.450 wt %. In some
embodiments, a combination of Mn and Cr may be equal to or greater
than 0.400 wt %. In some embodiments, a combination of Mn and Cr
may be equal to or greater than 0.350 wt %. In some embodiments, a
combination of Mn and Cr may be equal to or greater than 0.300 wt
%. In some embodiments, a combination of Mn and Cr may be equal to
or greater than 0.250 wt %. In some embodiments, a combination of
Mn and Cr may be equal to or greater than 0.200 wt %. In some
embodiments, a combination of Mn and Cr may be equal to or greater
than 0.150 wt %. In some embodiments, a combination of Mn and Cr
may be equal to or greater than 0.100 wt %. In some embodiments, a
combination of Mn and Cr may be equal to or greater than 0.040 wt
%.
[0070] In some variations, chromium may be equal to or less than
0.500 wt %. In some variations, chromium may be equal to or less
than 0.450 wt %. In some variations, chromium may be equal to or
less than 0.400 wt %. In some variations, chromium may be equal to
or less than 0.350 wt %. In some variations, chromium may be equal
to or less than 0.300 wt %. In some variations, chromium may be
equal to or less than 0.250 wt %. In some variations, chromium may
be equal to or less than 0.200 wt %. In some variations, chromium
may be equal to or less than 0.190 wt %. In some variations,
chromium may be equal to or less than 0.180 wt %. In some
variations, chromium may be equal to or less than 0.170 wt %. In
some variations, chromium may be equal to or less than 0.160 wt %.
In some variations, chromium may be equal to or less than 0.150 wt
%. In some variations, chromium may be equal to or less than 0.140
wt %. In some variations, chromium may be equal to or less than
0.130 wt %. In some variations, chromium may be equal to or less
than 0.120 wt %. In some variations, chromium may be equal to or
less than 0.110 wt %. In some variations, chromium may be equal to
or less than 0.100 wt %. In some variations, chromium may be equal
to or less than 0.095 wt %. In some variations, chromium may be
equal to or less than 0.090 wt %. In some variations, chromium may
be equal to or less than 0.050 wt %. In some variations, chromium
may be equal to or less than 0.010 wt %. In some variations,
chromium may be equal to or less than 0.005 wt %.
[0071] In some variations, chromium may be equal to or greater than
0 wt %. In some variations, chromium may be equal to or greater
than 0.005 wt %. In some variations, chromium may be equal to or
greater than 0.010 wt %. In some variations, chromium may be equal
to or greater than 0.040 wt %. In some variations, chromium may be
equal to or greater than 0.050 wt %. In some variations, chromium
may be equal to or greater than 0.090 wt %. In some variations,
chromium may be equal to or greater than 0.095 wt %. In some
variations, chromium may be equal to or greater than 0.100 wt %. In
some variations, chromium may be equal to or greater than 0.110 wt
%. In some variations, chromium may be equal to or greater than
0.120 wt %. In some variations, chromium may be equal to or greater
than 0.130 wt %. In some variations, chromium may be equal to or
greater than 0.140 wt %. In some variations, chromium may be equal
to or greater than 0.150 wt %. In some variations, chromium may be
equal to or greater than 0.160 wt %. In some variations, chromium
may be equal to or greater than 0.170 wt %. In some variations,
chromium may be equal to or greater than 0.180 wt %. In some
variations, chromium may be equal to or greater than 0.190 wt %. In
some variations, chromium may be equal to or greater than 0.200 wt
%. In some variations, chromium may be equal to or greater than
0.250 wt %. In some variations, chromium may be equal to or greater
than 0.300 wt %. In some variations, chromium may be equal to or
greater than 0.350 wt %. In some variations, chromium may be equal
to or greater than 0.400 wt %. In some variations, chromium may be
equal to or greater than 0.450 wt %.
Additional Non-Aluminum Elements
[0072] The disclosed 6000 series aluminum alloy may include other
elements as disclosed below.
[0073] In some variations, the alloy can include Cu. Without
wishing to be limited to any particular mechanism, effect, or mode
of action, Cu can improve corrosion resistance, and/or Cu can
influence color of the anodized alloy.
[0074] In some variations, copper may vary from 0.010 wt % to 0.050
wt %.
[0075] In some variations, copper may be equal to or less than
0.050 wt %. In some variations, copper may be equal to or less than
0.045 wt %. In some variations, copper may be equal to or less than
0.040 wt %. In some variations, copper may be equal to or less than
0.035 wt %. In some variations, copper may be equal to or less than
0.030 wt %. In some variations, copper may be equal to or less than
0.025 wt %. In some variations, copper may be equal to or less than
0.020 wt %. In some variations, copper may be equal to or less than
0.015 wt %.
[0076] In some variations, copper may be equal to or greater than
0.010 wt %. In some variations, copper may be equal to or greater
than 0.015 wt %. In some variations, copper may be equal to or
greater than 0.020 wt %. In some variations, copper may be equal to
or greater than 0.025 wt %. In some variations, copper may be equal
to or greater than 0.030 wt %. In some variations, copper may be
equal to or greater than 0.035 wt %. In some variations, copper may
be equal to or greater than 0.040 wt %. In some variations, copper
may be equal to or greater than 0.045 wt %.
[0077] In some variations, chromium may be equal to or less than
0.10 wt %. In some variations, chromium may be equal to or less
than 0.08 wt %. In some variations, chromium may be equal to or
less than 0.06 wt %. In some variations, chromium may be equal to
or less than 0.04 wt %. In some variations, chromium may be equal
to or less than 0.03 wt %. In some variations, chromium may be
equal to or less than 0.02 wt %. In some variations, chromium may
be equal to or less than 0.01 wt %. In some variations, chromium
may be equal to or less than 0.008 wt %. In some variations,
chromium may be equal to or less than 0.006 wt %. In some
variations, chromium may be equal to or less than 0.004 wt %. In
some variations, chromium may be equal to or less than 0.002 wt
%.
[0078] In some variations, zinc may be equal to or less than 0.20
wt %. In some variations, zinc may be equal to or less than 0.15 wt
%. In some variations, zinc may be equal to or less than 0.10 wt %.
In some variations, zinc may be equal to or less than 0.08 wt %. In
some variations, zinc may be equal to or less than 0.06 wt %. In
some variations, zinc may be equal to or less than 0.04 wt %. In
some variations, zinc may be equal to or less than 0.03 wt %. In
some variations, zinc may be equal to or less than 0.02 wt %. In
some variations, zinc may be equal to or less than 0.01 wt %. In
some variations, zinc may be equal to or less than 0.005 wt %. In
some variations, zinc may be equal to or less than 0.001 wt %.
[0079] In some variations, gallium may be equal to or less than
0.20 wt %. In some variations, gallium may be equal to or less than
0.15 wt %. In some variations, gallium may be equal to or less than
0.10 wt %. In some variations, gallium may be equal to or less than
0.08 wt %. In some variations, gallium may be equal to or less than
0.06 wt %. In some variations, gallium may be equal to or less than
0.04 wt %. In some variations, gallium may be equal to or less than
0.03 wt %. In some variations, gallium may be equal to or less than
0.02 wt %. In some variations, gallium may be equal to or less than
0.015 wt %. In some variations, gallium may be equal to or less
than 0.01 wt %. In some variations, gallium may be equal to or less
than 0.005 wt %. In some variations, gallium may be equal to or
less than 0.001 wt %.
[0080] In some variations, tin may be equal to or less than 0.20 wt
%. In some variations, tin may be equal to or less than 0.15 wt %.
In some variations, tin may be equal to or less than 0.10 wt %. In
some variations, tin may be equal to or less than 0.08 wt %. In
some variations, tin may be equal to or less than 0.06 wt %. In
some variations, tin may be equal to or less than 0.04 wt %. In
some variations, tin may be equal to or less than 0.01 wt %. In
some variations, tin may be equal to or less than 0.008 wt %. In
some variations, tin may be equal to or less than 0.006 wt %. In
some variations, tin may be equal to or less than 0.004 wt %. In
some variations, tin may be equal to or less than 0.002 wt %.
[0081] In some variations, vanadium may be equal to or less than
0.20 wt %. In some variations, vanadium may be equal to or less
than 0.15 wt %. In some variations, vanadium may be equal to or
less than 0.10 wt %. In some variations, vanadium may be equal to
or less than 0.08 wt %. In some variations, vanadium may be equal
to or less than 0.06 wt %. In some variations, vanadium may be
equal to or less than 0.04 wt %. In some variations, vanadium may
be equal to or less than 0.02 wt %. In some variations, vanadium
may be equal to or less than 0.01 wt %. In some variations,
vanadium may be equal to or less than 0.005 wt %. In some
variations, vanadium may be equal to or less than 0.001 wt %.
[0082] In some variations, calcium may be equal to or less than
0.001 wt %. In some variations, calcium may be equal to or less
than 0.0003 wt %. In some variations, calcium may be equal to or
less than 0.0002 wt %. In some variations, calcium may be equal to
or less than 0.0001 wt %.
[0083] In some variations, sodium may be equal to or less than
0.002 wt %. In some variations, sodium may be equal to or less than
0.0002 wt %. In some variations, sodium may be equal to or less
than 0.0001 wt %.
[0084] One or more of other elements, including chromium, boron,
zirconium, lithium, cadmium, lead, nickel, phosphorous, among
others, may be equal to or less than 0.01 wt %. One or more of
other elements, including chromium, boron, zirconium, lithium,
cadmium, lead, nickel, phosphorous, among others, may be equal to
or less than 0.008 wt %. One or more of these other elements may be
equal to or less than 0.006 wt %. One or more of these other
elements may be equal to or less than 0.004 wt %. One or more of
other elements may be equal to or less than 0.002 wt %.
[0085] In some variations, a total of other elements may not exceed
0.20 wt %. In some variations, a total of other elements may not
exceed 0.10 wt %. In some variations, a total of other elements may
not exceed 0.08 wt %. In some variations, a total of other elements
may not exceed 0.06 wt %. In some variations, a total of other
elements may not exceed 0.04 wt %.
[0086] In some variations, a total of non-aluminum elements may not
exceed 3.5 wt %. In some variations, a total of non-aluminum
elements may not exceed 3.0 wt %. In some variations, a total of
non-aluminum elements may not exceed 2.5 wt %. In some variations,
a total of non-aluminum elements may not exceed 2.0 wt %. In some
variations, a total of non-aluminum elements may not exceed 1.5 wt
%. In some variations, a total of non-aluminum elements may not
exceed 1.0 wt %. In some variations, a total of non-aluminum
elements may not exceed 0.5 wt %.
Process for Cleaning and Removing Oxides from Scrap
[0087] Scrap can have a large surface area/volume ratio compared to
alloys made from virgin material. The large surface area of the
scrap can include a substantial quantity of oxides, such as
aluminum oxides. Scrap may also include impurities, such as Fe or
Ti, among others, compared to conventional 6000 series aluminum
alloys, 1000 series alloys, or virgin alloys of the 6000 series
aluminum alloys.
[0088] The cleaning process may include removing oxides by
re-melting scrap and flowing oxides and skim off the oxides. The
cleaning process may also include removing organic contaminants by
chemical solvent or solution or heating.
[0089] The disclosed recycled 6000 series aluminum alloys can be
made from up to 100% Al scrap, and can be used to form a part by
extrusion. The disclosed recycled 6000 series aluminum alloys can
also include scrap extrusion or sheet material. The disclosed
methods can include or exclude primary aluminum or virgin
aluminum.
[0090] FIG. 2 depicts a flow chart for a recycling process from
scrap in accordance with embodiments of the disclosure. As shown, a
process 200 includes obtaining an aluminum alloy from a chip source
or manufacturing scrap at operation 202. The manufacturing scrap
(e.g. chips) is melted to form a melted aluminum alloy at operation
204. After the melt is cooled to room temperature, the alloys may
go through various heat treatments, such as casting,
homogenization, extruding, rolling, solution heat treatment, and
aging, among others.
[0091] In some embodiments, a melt for an alloy can be prepared by
heating the alloy including the composition.
[0092] The melted scrap may be billet or slab casted to form an
extrusion at operation 206, and then homogenized. In some
embodiments, the cast alloys can be homogenized by heating to an
elevated temperature and holding at the elevated temperature for a
period of time, such as at an elevated temperature of 520.degree.
C. to 620.degree. C. for a period of time, e.g. 8-18 hours.
[0093] As shown in FIG. 2, homogenization is used for extrusion and
rolling. Homogenization refers to a process in which the alloy is
soaked at an elevated temperature for a period of time.
Homogenization can reduce chemical or metallurgical segregation,
which may occur as a natural result of solidification in some
alloys. Homogenization can also be used to transform long, narrow
AlFeSi particles into small, broken up AlFeSi and AlFeSiMn
particles. It will be appreciated by those skilled in the art that
the heat treatment conditions (e.g. temperature and time) may
vary.
[0094] The homogenized alloy may be extruded or rolled at operation
208. Extrusion is a process for converting a metal billet into
lengths of uniform cross section by forcing the metal to flow
plastically through a die orifice.
[0095] A product, such as a component of part, may be fabricated
from the extruded or rolled aluminum alloy obtained at operation
210.
[0096] In some embodiments, the extruded alloys can be preheated to
an elevated temperature, e.g. about 400.degree. C. and ramped up to
a higher temperature, e.g. above 500.degree. C. for extrusion. The
extrusion and solution heat-treatment may occur simultaneously at
the higher elevated temperature, e.g. about 500.degree. C. The
solution heat treatments can alter the strength of the alloy.
[0097] In some embodiments, the chip source or scrap may also
include a portion of disclosed 6000 series aluminum alloys in
addition to the scrap from various sources.
[0098] After the solution treatment, the alloy can be aged at a
temperature of 125 to 225.degree. C. for about a period of time,
e.g. 6-10 hours, and then quenched with water. Aging is a heat
treatment at an elevated temperature, and may induce a
precipitation reaction to form precipitates Mg--Si. It will be
appreciated by those skilled in the art that the heat treatment
condition (e.g. temperature and time) may vary.
[0099] In further embodiments, the disclosed 6000 series aluminum
alloys may be optionally subjected to a stress-relief treatment
between the solution heat-treatment and the aging heat-treatment.
The stress-relief treatment can include stretching the alloy,
compressing the alloy, or combinations thereof.
Cosmetic Appeal
[0100] The aluminum alloys disclosed herein typically have more Fe
than in conventional aluminum alloys. Aluminum alloys having higher
amounts of iron particularly by having a more gray color. The scrap
can include more Fe than the conventional 6000 series aluminum
alloys, or Reference Alloy 2. As described above, the recycled
aluminum alloys described herein have more iron than that is
typically present in virgin aluminum alloys for alloys with
cosmetic appeal.
[0101] Iron can have negative effects on the cosmetic appeal by
creating an unattractive gray color. In addition to having a
negative effect on cosmetics, iron contributes to the formation of
iron-aluminum-silicon particles during processing. The acquisition
of Si by the Fe particles reduces the amount of Si available for
strengthening. As such, more Si is added to the alloys disclosed
herein. The presently disclosed alloys also have increased silicon
and increased magnesium to form more Mg.sub.xSi.sub.y particles for
strengthening purpose, compared to Reference Alloys 1 and 2.
[0102] In some embodiments, the disclosed 6000 series aluminum
alloys can be anodized. Anodizing is a surface treatment process
for metal, most commonly used to protect aluminum alloys. Anodizing
uses electrolytic passivation to increase the thickness of the
natural oxide layer on the surface of metal parts. Anodizing may
increase corrosion resistance and wear resistance, and may also
provide better adhesion for paint primers and glues than bare
metal. Anodized films may also be used for cosmetic effects, for
example, it may add interference effects to reflected light.
[0103] Surprisingly, the disclosed recycled 6000 series aluminum
alloys have higher Si content than Reference Alloy 1, yet still the
same or improved cosmetic appeal as those with lower iron, silicon,
and magnesium. In particular, after anodizing they do not take a
yellowish or gray color, and do not have increased cosmetic defects
such as mottling, grain lines, black lines, discoloration, white
dots, oxidation, and line mark, among others.
[0104] In some embodiments, the disclosed 6000 series aluminum
alloys can form enclosures for electronic devices. The enclosures
may be designed to have a blasted surface finish absent of streaky
lines. Blasting is a surface finishing process, for example,
smoothing a rough surface or roughening a smooth surface. Blasting
may remove surface material by forcibly propelling a stream of
abrasive media against a surface under high pressure.
[0105] Standard methods may be used for evaluation of cosmetics
including color, gloss and haze. The color of objects may be
determined by the wavelength of light that is reflected or
transmitted without being absorbed, assuming incident light is
white light. The visual appearance of objects may vary with light
reflection or transmission. Additional appearance attributes may be
based on the directional brightness distribution of reflected light
or transmitted light, commonly referred to as glossy, shiny, dull,
clear, hazy, among others. The quantitative evaluation may be
performed based on ASTM Standards on Color & Appearance
Measurement or ASTM E-430 Standard Test Methods for Measurement of
Gloss of High-Gloss Surfaces, including ASTM D523 (Gloss), ASTM
D2457 (Gloss on plastics), ASTM E430 (Gloss on high-gloss surfaces,
haze), and ASTM D5767 (DOI), among others. The measurements of
gloss, haze, and DOI may be performed by testing equipment, such as
Rhopoint IQ.
[0106] In some embodiments, color may be quantified by parameters
L*, a*, and b*, where L* stands for light brightness, a* stands for
color between red and green, and b* stands for color between blue
and yellow. For example, high b* values suggest an unappealing
yellowish color, not a gold yellow color. Nearly zero parameters a*
and b* suggest a neutral color. Low L* values suggest dark
brightness, while high L* value suggests great brightness. For
color measurement, testing equipment, such as X-Rite ColorEye XTH,
X-Rite Coloreye 7000 may be used. These measurements are according
to CIE/ISO standards for illuminants, observers, and the L*, a*,
and b* color scale. For example, the standards include: (a) ISO
11664-1:2007(E)/CIE S 014-1/E:2006: Joint ISO/CIE Standard:
Colorimetry--Part 1: CIE Standard Colorimetric Observers; (b) ISO
11664-2:2007(E)/CIE S 014-2/E:2006: Joint ISO/CIE Standard:
Colorimetry--Part 2: CIE Standard Illuminants for Colorimetry, (c)
ISO 11664-3:2012(E)/CIE S 014-3/E:2011: Joint ISO/CIE Standard:
Colorimetry--Part 3: CIE Tristimulus Values; and (d) ISO
11664-4:2008(E)/CIE S 014-4/E:2007: Joint ISO/CIE Standard:
Colorimetry--Part 4: CIE 1976 L*, a*, and b* Color Space.
[0107] In some variations, L* is from 70 to 100. In some
variations, L* is at least 70. In some variations, L* is at least
75. In some variations, L* is at least 80. In some variations, L*
is at least 85. In some variations, L* is at least 90. In some
variations, L* is at least 95. In some variations, L* is less than
or equal to 100. In some variations, L* is less than or equal to
95. In some variations, L* is less than or equal to 90. In some
variations, L* is less than or equal to 85. In some variations, L*
is less than or equal to 80. In some variations, L* is less than or
equal to 75.
[0108] In some variations, a* is from -2 to 2. In some variations,
a* is at least -2. In some variations, a* is at least -1.5. In some
variations, a* is at least -1.0. In some variations, a* is at least
-0.5. In some variations, a* is at least 0.0. In some variations,
a* is at least 0.5. In some variations, a* is at least -0.5. In
some variations, a* is at least 1.0. In some variations, a* is at
least 1.5. In some variations, a* is less than or equal to 2.0. In
some variations, a* is less than or equal to 1.5. In some
variations, a* is less than or equal to 1.0. In some variations, a*
is less than or equal to 0.5. In some variations, a* is less than
or equal to 0.0. In some variations, a* is less than or equal to
2.0. In some variations, a* is less than or equal to -0.5. In some
variations, a* is less than or equal to -1.0. In some variations,
a* is less than or equal to -1.5.
[0109] In some variations, b* is from -2 to 2. In some variations,
b* is at least -2. In some variations, b* is at least -1.5. In some
variations, a is at least -1.0. In some variations, b* is at least
-0.5. In some variations, b* is at least 0.0. In some variations,
b* is at least 0.5. In some variations, b* is at least -0.5. In
some variations, b* is at least 1.0. In some variations, b* is at
least 1.5. In some variations, b* is less than or equal to 2.0. In
some variations, b* is less than or equal to 1.5. In some
variations, b* is less than or equal to 1.0. In some variations, b*
is less than or equal to 0.5. In some variations, b* is less than
or equal to 0.0. In some variations, b* is less than or equal to
2.0. In some variations, b* is less than or equal to -0.5. In some
variations, b* is less than or equal to -1.0. In some variations,
b* is less than or equal to -1.5.
Mechanical Properties
[0110] Yield strengths of the alloys may be determined via ASTM
8557, which covers the testing apparatus, test specimens, and
testing procedure for tensile testing.
[0111] The 6000 series aluminum alloy can be extruded or rolled
with the conventional process for aluminum alloys to have the
mechanical properties, including yield strength, tensile strength,
elongation, and hardness, to be the same as the aluminum alloy
without any scrap.
[0112] The mechanical properties have an upper limit, which allows
the alloy to be formed with dimensional consistency. The disclosed
recycled 6000 series aluminum alloys can exceed the tensile
strength and hardness upper limit of other cosmetic aluminum
alloys. However, the range of the tensile strength and hardness
remains unchanged, i.e. within the range between lower limit and
upper limit. The unchanged range allows the dimension consistency
during forming process, such as extrusion.
[0113] In some variations, the alloy has a yield strength of at
least 270 MPa. In some variations, the alloy has a yield strength
of at least 280 MPa. In some variations, the alloy has a yield
strength of at least 290 MPa. In some variations, the alloy has a
yield strength of at least 300 MPa. In some variations, the alloy
has a yield strength of at least 310 MPa. In some variations, the
alloy has a yield strength of at least 320 MPa.
[0114] In some variations, the alloy has a tensile strength of at
least 300 MPa. In some variations, the alloy has a tensile strength
of at least 310 MPa. In some variations, the alloy has a tensile
strength of at least 320 MPa. In some variations, the alloy has a
tensile strength of at least 330 MPa. In some variations, the alloy
has a tensile strength of at least 340 MPa.
[0115] In some variations, the alloy has an elongation from 8% to
16%.
[0116] In some variations, the alloy has an elongation less than or
equal to 16%. In some variations, the alloy has an elongation less
than or equal to 14%. In some variations, the alloy has an
elongation less than or equal to 12%. In some variations, the alloy
has an elongation less than or equal to 10%.
[0117] In some variations, the alloy has an elongation equal to or
greater than 8%. In some variations, the alloy has an elongation
equal to or greater than 10%. In some variations, the alloy has an
elongation equal to or greater than 12%. In some variations, the
alloy has an elongation equal to or greater than 14%.
Dimensional Consistency from Part to Part
[0118] The dimensional consistency from part to part is evaluated
for disclosed alloys.
[0119] Results indicate that the dimensional consistency of the
disclosed alloys all match or exceed the dimensional consistency of
the primary or virgin aluminum alloys, regardless of the sources
for the scrap, or Reference Alloys 1 and 2.
Thermal Conductivity
[0120] The disclosed 6000 series aluminum alloys can also have a
thermal conductivity of at least 180 W/mK, which helps heat
dissipation of the electronic devices. In various embodiments, the
thermal conductivity of the recycled alloys can be at least 190
W/mK. In various embodiments, the thermal conductivity of the
recycled alloys can be at least 200 W/mK. In various embodiments,
the thermal conductivity of the recycled alloys can be at least 210
W/mK. In various embodiments, the thermal conductivity of the
recycled alloys can be at least 220 W/mK. The thermal conductivity
varies with alloy composition and thermal heat treatment. The
thermal conductivity measured for the disclosed alloys range from
180 to 230 W/mK.
[0121] In various embodiments, the thermal conductivity of the
recycled alloys can be equal to or greater than 165 W/mK. In
various embodiments, the thermal conductivity of the recycled
alloys can be equal to or greater than 175 W/mK. In various
embodiments, the thermal conductivity of the recycled alloys can be
equal to or greater than 185 W/mK. In various embodiments, the
thermal conductivity of the recycled alloys can be equal to or
greater than 195 W/mK.
[0122] In various embodiments, the thermal conductivity of the
recycled alloys can be equal to and less than 200 W/mK. In various
embodiments, the thermal conductivity of the recycled alloys can be
equal to and less than 190 W/mK. In various embodiments, the
thermal conductivity of the recycled alloys can be equal to and
less than 180 W/mK. In various embodiments, the thermal
conductivity of the recycled alloys can be equal to and less than
170 W/mK.
Microstructure
[0123] Microstructure can be characterized by average grain size,
largest grain size, and grain aspect ratio. The microstructure
related to the mechanical properties, such as yield strength,
tensile strength, and elongation among others.
EXAMPLES
[0124] The following examples are for illustration purposes only.
It will be apparent to those skilled in the art that many
modifications, both to materials and methods, may be practiced
without departing from the scope of the disclosure.
Example 1
[0125] Table 1 lists the compositions for Alloys 1-7 with different
elemental compositions of disclosed recycled aluminum alloy. Alloys
1-7 were formed from manufacturing scrap. Table 1 lists the
composition in wt %. Alloys 1-7 have various combinations of Mg and
Si as well as Mg/Si ratios. Alloys 1-7 had higher amounts of Si and
Mg than Reference Alloy 1. Alloys 1-7 had the same amounts of Fe
and Cu as Reference Alloy 1. Alloys 1-4 and 7 had the same amounts
of Mn as Reference Alloy 1, but Alloys 5-6 had Mn contents from
0.19 wt % to 0.21 wt %, which was much higher than Alloys 1-4 and
7. Mn can help break up the coarse Al--Fe--Si particles or AlFeSi
particles that form during casting. However, Mn can increase the
anodization b* color.
TABLE-US-00001 TABLE 1 Composition in wt % for Various Al Alloys
Alloy 1 Alloy 2 Alloy 3 Alloy 4 Alloy 5 Alloy 6 Alloy 7 Mg/Si 1.05
to 0.67 to 0.70 to 0.65 to 0.67 to 0.70 to 0.92 to Ratio 1.22 0.81
0.83 0.75 0.81 0.83 1.00 Mg 0.82 to 0.52 to 0.62 to 0.67 to 0.52 to
0.62 to 0.72 to 0.88 0.58 0.68 0.73 0.58 0.68 0.78 Si 0.72 to 0.72
to 0.82 to 0.97 to 0.72 to 0.82 to 0.72 to 0.78 0.78 0.88 1.03 0.78
0.88 0.78 Fe 0.10 to 0.10 to 0.10 to 0.10 to 0.10 to 0.10 to 0.10
to 0.50 0.50 0.50 0.50 0.50 0.50 0.50 Mn 0.0005 0.0005 0.0005
0.0005 0.19 to 0.19 to 0.0005 to to 0.090 to 0.090 to 0.090 to
0.090 0.21 0.21 0.090 or or 0.015 or 0.015 or 0.015 or 0.015 0.015
to to 0.025 to 0.025 to 0.025 to 0.025 0.025 Cr Less Less Less Less
Less Less Less than than than than than than than 0.10 0.10 0.10
0.10 0.10 0.10 0.10 Cu 0.010 to 0.010 to 0.010 to 0.010 to 0.010 to
0.010 to 0.010 to 0.050 0.050 0.050 0.050 0.050 0.050 0.050 Ni 0 to
0 to 0 to 0 to 0 to 0 to 0 to 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Zn
0 to 0 to 0 to 0 to 0 to 0 to 0 to 0.20 0.20 0.20 0.20 0.20 0.20
0.20 Ti 0 to 0 to 0 to 0 to 0 to 0 to 0 to 0.10 0.10 0.10 0.10 0.10
0.10 0.10
[0126] Table 2 lists the compositions of Reference Alloy 2,
Reference Alloy 1, disclosed alloy, and Reference Alloy 3. The
Reference Alloy 2 was a primary or virgin aluminum alloy, which was
not recycled. The Reference Alloy 1 was cosmetic aluminum alloy,
which was disclosed in U.S. patent application Ser. No. 16/530,830,
entitled "Recycled Aluminum Alloys From Manufacturing Scrap with
Cosmetic Appeal," filed on Aug. 2, 2019, which is incorporated by
reference in its entirety.
[0127] As shown in Table 2, Reference Alloy 2 includes a typical
precipitate of Mg.sub.2Si, which would require a Si/Mg ratio of 0.5
or Mg/Si ratio of 2. Reference Alloy 1 has a Mg/Si ratio greater
than 1. However, the disclosed alloy (E.g. Alloys 2-3 and 5-7) has
a Mg/Si ratio of 0.60 to 1.0, which is lower than the Mg/Si ratio
of Reference Alloy 1.
TABLE-US-00002 TABLE 2 Composition in wt % for Various Aluminum
Alloys Reference Alloy Reference Alloy Alloys Sample 1 2 2, 3, and
5-7 Mg/Si Ratio >1.0 2.0 0.65 to 1.0 Mg 0.45 to 0.95 0.45 to
0.60 0.50 to 0.80 Si 0.35 to 0.80 0.35 to 0.50 0.70 to 0.90 Fe 0.10
to 0.50 0.04 to 0.14 0.10 to 0.50 Mn 0.0005 to 0.090 0.0005 to
0.025 0.0005 to 0.21 or 0.015 to 0.025 or 0.015 to 0.21 Cr Less
than 0.10 Less than 0.10 Less than 0.10 Cu 0.010 to 0.050
.ltoreq.0.010 0.010 to 0.050 Ni 0 to 0.01 0 to 0.01 0 to 0.01 Zn 0
to 0.20 0 to 0.20 0 to 0.20 Ti 0 to 0.10 0 to 0.10 0 to 0.10
[0128] FIG. 3 shows Si versus Mg compositions for various aluminum
alloys in accordance with embodiments of the disclosure. As shown
in FIG. 3, various aluminum alloys have different Si and Mg
compositions, including commercial alloys 6063, 6061, 6013, 6082,
and 6005. Each of alloys 6063, 6061, 6082, 6013, and 6005 had the
Si and Mg composition ranges within corresponding boxes 302, 304,
306, 308, and 310. As shown in FIG. 3, the compositions of
Reference Alloy 1 and Reference Alloy 2 were in the ranges of
commercial alloy 6063. For example, alloy 6063 had Si from about
0.18 wt % to about 0.58 wt % and Mg from about 0.46 wt % to about
0.58 wt %. Also, the Mg/Si ratio was less than 1.0 for both
Reference Alloys 1 and 2.
[0129] FIG. 4 shows Si versus Mg compositions for Alloys 1-11 in
accordance with embodiments of the disclosure. As shown in FIG. 4,
Alloys 1-11 have different Si and Mg compositions and thus
different Mg/Si ratios. The boundaries of the boxes for Alloys 1-11
defined the Si and Mg composition ranges for Alloys 1-11. As shown,
the Mg/Si ratios of Alloys 2-4 and 5-8 were less than or equal to
1.0, the Mg/Si ratios of Alloys 1 and 10 were slightly greater than
1.0, while the Mg/Si ratios of Alloys 9 and 11 were higher than
Alloys 1 and 10, up to about 1.8. These compositions and Mg/Si
ratios of Alloys 1-7 are listed in Tables 1 and 2. The compositions
and Mg/Si ratios of Alloys 8-11 are listed in Table 3.
[0130] Alloys 1 and 4 had higher Mg and/or Si than other Alloys 2-3
and 5-7, and were found to be more challenges with processing, such
as extrusion, or cosmetic appeal, and were deselected for further
experiments. For example, Sample 4 had Si from 0.97 wt % to 1.03 wt
%, which affected the cosmetic appeal. Sample 1 had Mg from 0.82 wt
% to 0.88 wt %, which affected the extrusion. Combination of higher
Mg or Si in Alloys 1 and 4 results in higher stability of
Mg.sub.2Si phase than other alloys, making them more challenging to
process including homogenization and extrusion. Alloys 2, 3, 5, 6,
and 7 were selected for further prototypes and experiments.
[0131] The data of mechanical properties and microstructure
corresponding to different preparations were presented in box
plots, as shown in FIGS. 6-11.
[0132] FIG. 5 illustrates higher extrusion speed for the disclosed
recycled aluminum alloy than 7000 series alloys (e.g. Reference
Alloy 3) in accordance with embodiments of the disclosure.
Reference Alloy 3 was used as a reference alloy for yield strength.
Reference Alloy 3 was disclosed in U.S. Pat. No. 10,208,371,
entitled "ALUMINUM ALLOYS WITH HIGH STRENGTH AND COSMETIC APPEAL,"
by Misra et al., issued on February, 2019, which is incorporated by
reference in its entirety. Reference Alloy 3 includes 3.4 to 4.9 wt
% Zn, 1.3 to 2.1 wt % Mg, no greater than 0.06 wt % Cu, no greater
than 0.06 wt % Zr, 0.06 to 0.08 wt % Fe, and no greater than 0.05
wt % Si. Reference Alloy 3 also has a wt % ratio of Zn to Mg from
2.5 to 3.5.
[0133] The extrusion speed of the disclosed alloy was normalized
against Reference Alloy 3. As shown in FIG. 5, the extrusion speed
of the disclosed alloy was about 60% higher than the extrusion
speed for Reference Alloy 3. The extrusion speeds of these alloys
were determined at an extrusion exit temperature ranging from
544.degree. C. to 550.degree. C.
[0134] In some variations, the alloy may have an extrusion speed of
at least 20% higher than 7000 series alloys. In some variations,
the alloy may have an extrusion speed of at least 30% higher than
7000 series alloys. In some variations, the alloy may have an
extrusion speed of at least 40% higher than 7000 series alloys. In
some variations, the alloy may have an extrusion speed of at least
50% higher than 7000 series alloys. In some variations, the alloy
may have an extrusion speed of at least 60% higher than 7000 series
alloys.
[0135] FIG. 6 illustrates the yield strength for extrusion samples
formed of Alloys 3 and 7 in accordance with an embodiment of the
disclosure. As shown in FIG. 6, Alloys 3 and 7 of the disclosed
alloy revealed a yield strength between 280 MPa and 310 MPa, which
was significant higher than that of Reference Alloy 1 and Reference
Alloy 2, e.g. about 30% higher than that of Reference Alloy 1 and
Reference Alloy 2. Also, the yield strength of the disclosed alloy
was close to the yield strength of 7000 series alloy, e.g.
Reference Alloy 3 with a yield strength between 295 MPa and 330
MPa.
[0136] FIG. 7 illustrates the tensile strength for extrusion
samples formed of the disclosed alloy, in accordance with an
embodiment of the disclosure. As shown in FIG. 7, Alloys 3 and 7 of
the disclosed alloy revealed a tensile strength between 300 MP and
330 MPa, which was significant higher than that of Reference Alloy
1 and Reference Alloy 2. Also, the tensile strength of 7000 series
alloy, e.g. Reference Alloy 3 was between 340 MPa and 380 MPa.
[0137] FIG. 8 illustrates the elongation for extrusion samples
formed of the disclosed alloy. As shown in FIG. 8, Alloys 3 and 7
of the disclosed alloy revealed an elongation between 8% and 12%,
which was significant lower than that of Reference Alloy 1,
Reference Alloy 2, and Reference Alloy 3.
[0138] Microstructure can be characterized by average grain size,
largest grain size, and grain aspect ratio. FIG. 9 illustrates the
average grain size for extrusion samples formed of Alloys 3 and 7.
As shown, the average grain size varied from about 70 .mu.m to
about 120 .mu.m. In some variations, the alloy has an average grain
size equal to or less than 130 .mu.m.
[0139] FIG. 10 illustrates the largest grain size for extrusion
samples formed of Alloy 3 in accordance with an embodiment of the
disclosure. FIG. 11 illustrates the grain aspect ratio for
extrusion samples formed of Alloy 3 in accordance with an
embodiment of the disclosure. As shown in FIG. 11, the aspect ratio
of the grain is between a minimum value of 0.82 and a maximum value
of 1.20 with a median value of 1.05. In some variations, the alloy
has a grain aspect ratio between 0.8 and 1.3.
[0140] As shown in FIGS. 9-11, the microstructure of the disclosed
alloy was similar to that of Reference Alloy 1 and Reference Alloy
2 as well as Reference Alloy 3.
[0141] FIG. 12 illustrates yield strengths, elongation, and
anodization color b* for Alloys 2, 3, 5, 6, and 7 in accordance
with embodiments of the disclosure.
[0142] As shown in FIG. 12, Alloy 6 had the highest yield strength
and the lowest elongation among all alloy samples. Alloy 6 had more
Mn than Alloy 3, while Si and Mg of Alloy 6 remained the same as
Alloy 3. Alloy 6 has an average yield strength of about 302 MPa,
while Alloy 3 had an average yield strength of about 294 MPa. The
slight increase in the yield strength of Alloy 6 from Alloy 3 was
likely caused by the addition of Mn.
[0143] Also, Alloy 5 had slightly higher yield strength and lower
elongation than Alloy 2. Alloy 5 only had more Mn than Alloy 2,
while Si and Mg of Alloy 5 remained the same as Alloy 2. Alloy 5
has an average yield strength slightly higher than Alloy 2, which
was also likely caused by the addition of Mn.
[0144] Turning to anodization color b* now, as shown in FIG. 12,
Alloy 7 had the lowest anodization color b* compared to Alloys 2-3
and 5-6. Alloys 5 and 6 had higher anodization color b* than Alloys
2-3 and 7. Alloys 5 and 6 included 0.19 to 0.21 wt % Mn, which were
higher than Alloys 2-3 and 7 and may contribute the increase of the
anodization color b*. The disclosed alloy revealed the color
similar to that of Reference Alloys 1 and 2.
[0145] FIG. 13 shows the comparison of yield strengths of various
aluminum alloys in accordance with embodiments of the disclosure.
As shown, the disclosed alloy (e.g. Alloys 2-3, and 5-7) had the
same yield strength as Reference Alloy 3, but higher yield strength
than alloys Reference Alloy 2 and Reference Alloy 1.
[0146] Alloy 7 had the desirable anodization color b*, but did not
have the ano cosmetic appeal as desired due to the presence of
undesirable large AlFeSi particles. Further experiments were
performed in alloys varying compositions in Mg, Mn, and Si.
Specifically, Mg content and Mn content were increased and Si was
lowered to determine if the cosmetic appeal can be improved to meet
the desired performance while the alloys can still be processable.
Higher Mg/Si ratio was observed to lower the anodization color b*.
In some variations, Alloys 8-11 had higher Mg/Si ratios, increasing
extrusion time.
[0147] Alloy 1 was found to be more difficult to extrude than
Alloys 2-7 due to slightly higher Mg amount than Alloys 2-7. Some
extrusion process variations were made to extrude Alloy 1.
Adjustment of extrusion parameters including speed and temperature
is necessary for successfully Alloy 1 extrusion.
Example 2
[0148] Table 3 lists the compositions of Alloys 1, 7, and 8-11.
Alloys 1 and 7 were used for comparison with Alloys 8-11. Alloys
8-11 achieved similar extrudability to Reference Alloy 2 and
reasonable cosmetics appeal. Alloys 8-11 also achieved a good
combination of microstructure, color, strength, and ductility
within different Si, Mg, Mn compositions from Alloys 2-7.
TABLE-US-00003 TABLE 3 Composition in wt % for Various Al Alloys
Alloy 1 Alloy 7 Alloy 8 Alloy 9 Alloy 10 Alloy 11 Mg/Si 1.05 to
0.92 to 0.92 to 1.22 to 1.05 to 1.50 to Ratio 1.22 1.00 1.00 1.46
1.22 1.79 Mg 0.82 to 0.72 to 0.72 to 0.77 to 0.82 to 0.87 to 0.88
0.78 0.78 0.83 0.88 0.93 Si 0.72 to 0.72 to 0.72 to 0.57 to 0.72 to
0.52 to 0.78 0.78 0.78 0.63 0.78 0.58 Fe 0.10 to 0.10 to 0.10 to
0.10 to 0.10 to 0.10 to 0.50 0.50 0.50 0.50 0.50 0.50 Mn 0.015 to
0.015 to 0.090 to 0.015 to 0.090 to 0.015 to 0.025 0.025 0.110
0.025 0.110 0.025 Cr Less Less Less Less Less Less than than than
than than than 0.10 0.10 0.10 0.10 0.10 0.10 Cu 0.010 to 0.010 to
0.010 to 0.010 to 0.010 to 0.010 to 0.050 0.050 0.050 0.050 0.050
0.050 Ni 0 to 0 to 0 to 0 to 0 to 0 to 0.01 0.01 0.01 0.01 0.01
0.01 Zn 0 to 0 to 0 to 0 to 0 to 0 to 0.20 0.20 0.20 0.20 0.20 0.20
Ti 0 to 0 to 0 to 0 to 0 to 0 to 0.10 0.10 0.10 0.10 0.10 0.10
[0149] As shown in Table 3, Alloys 1, 7, 8, and 10 had the same Si
content, i.e. 0.72 to 0.78 wt %. Alloys 8 and 10 had 0.090 to 0.110
wt % Mn, which was higher than Alloys 1 and 7. The difference
between Alloys 8 and 10 was in Mg. Alloy 8 had 0.72 to 0.78 wt %
Mg, which was slightly lower than 0.82-0.88 wt % Mg for Alloy 10,
while other elements remained unchanged.
[0150] There was one element Mn slightly different between Alloy 7
and Alloy 8. Alloy 8 had slightly higher Mn than Alloy 7, i.e.
0.090 to 0.110 wt % Mn for Alloy 8 vs 0.0005 to 0.090 wt % Mn for
Alloy 7.
[0151] There was one element Mn slightly different between Alloy 1
and Alloy 10. Alloy 10 had slightly higher Mn than Alloy 1, i.e.
0.090 to 0.110 wt % Mn for Alloy 10 vs 0.0005 to 0.090 wt % Mn for
Alloy 1.
[0152] Alloys 9 and 11 had lower Si contents than Alloys 1, 7, 8,
and 10. The difference between Alloys 9 and 11 were in Mg and Si.
Alloy 9 had slightly lower Mg than Alloy 11, but slightly higher Si
than Alloy 11. For example, Alloy 9 had 0.57 to 0.63 wt % Si and
0.77 to 0.83 wt % Mg, while Alloy 11 had 0.52 to 0.58 wt % Si and
0.87 to 0.93 wt % Mg.
[0153] FIG. 14 illustrates yield strengths for extrusion samples
formed of Alloys 1 and 7-11 in accordance with embodiments of the
disclosure. As shown in FIG. 14, Reference Alloy 2 had yield
strengths ranging from about 210 MPa to about 260 MPa. Reference
Alloy 3 had yield strengths ranging from about 300 MPa to about 330
MPa. Alloy 7 had yield strengths ranging from about 290 MPa to
about 310 MPa. Alloy 1 had yield strengths ranging from about 305
MPa to about 315 MPa. Alloys 8 and 10 had yield strengths ranging
from about 325 MPa to about 335 MPa.
[0154] An average yield strength of Alloy 1 was about 310 MPa,
which was about 10 MPa higher than an average yield strength of 300
MPa of Alloy 7. Alloy 1 included additional 0.1 wt % Mg, which may
provide slightly higher yield strength than Alloy 7.
[0155] Average yield strengths of Alloys 8 and 10 were about 330
MPa, which was about 30 MPa higher than the average yield strength
of 300 MPa of Alloy 7. Alloys 8 and 10 included about 0.090 to
0.110 wt % Mn. The additional Mn helps form smaller AlFe(Mn)Si
particles that may result in grain refinement and higher yield
strength than Alloy 7. Note that AlFe(Mn)Si particles may be
located at grain boundaries during casting. Then, recrystallization
can occur to form new grains during extrusion such that these
AlFe(Mn)Si particles may not be located at the grain boundaries in
an extruded profile.
[0156] Alloy 9 had yield strengths ranging from about 270 to about
285 MPa. Alloy 11 had yield strengths ranging from about 250 to
about 270 MPa. Alloy 9 included 0.57 to 0.63 wt % Si, which was
lower than 0.72 to 0.78 wt % Si for Alloy 7. Alloy 11 included 0.52
to 0.58 wt % Si, which even lower than Alloy 9. The lower Si
contents in Alloys 9 and 11 resulted in lower yield strength than
that of Alloy 7.
[0157] FIG. 15 illustrates tensile strengths for extrusion samples
formed of Alloys 1 and 7-11 in accordance with embodiments of the
disclosure. As shown in FIG. 15, Reference Alloy 2 had tensile
strengths ranging from about 240 MPa to about 280 MPa. Reference
Alloy 3 had tensile strengths ranging from about 345 MPa to about
375 MPa. Alloy 7 had tensile strengths ranging from about 305 MPa
to about 320 MPa with an average tensile strength of about 310 MPa.
Alloy 1 had tensile strengths ranging from about 320 MPa to about
330 MPa with an average tensile strength of about 325 MPa. Alloys 8
and 10 had tensile strengths ranging from about 335 MPa to about
345 MPa with an average tensile strength of about 340 MPa, which
was about 15 MPa and 25 MPa higher than Alloys 1 and 7,
respectively. Alloys 8 and 10 included about 0.090 to 0.110 wt %
Mn, which may form higher amount of constituent AlFeMnSi particles
that may result in grain refinement and higher tensile strength
than Alloys 7 and 1.
[0158] Alloy 9 had tensile strengths ranging from about 290 to
about 300 MPa. Alloy 11 had tensile strengths ranging from about
270 to about 290 MPa. The lower Si contents in Alloys 9 and 11
resulted in lower tensile strengths than that of Alloy 7.
[0159] FIG. 16 illustrates elongations for extrusion samples formed
of Alloys 1 and 7-11 in accordance with embodiments of the
disclosure. As shown in FIG. 16, Reference Alloy 2 had elongations
ranging from 8% to 19% with an average elongation of about 13.5%.
Reference Alloy 3 had elongations ranging from 16% to 22% with an
average elongation of about 18.5%. Alloy 7 had elongations ranging
from 9% to 13% with an average elongation of about 10.5%. Alloy 1
had elongations ranging from 9% to 11% with an average elongation
of about 10%. Alloys 8 and 10 had elongations ranging from 12% to
15% with average elongations of about 13.5% to 14%. Surprisingly,
Alloys 8 and 10 had an elongation about 3% to 4% higher than Alloys
1 and 7.
[0160] Generally, for the 6000 series alloys including Reference
Alloy 2, Alloys 1, 7, 8, and 10, lower elongation would be expected
with increased yield strength. For example, Reference Alloy 2 had
an average yield strength of about 230 MPa, which was about 30%
lower than an average yield strength of about 300 MPa for Alloy 7,
while the average elongation of Reference Alloy 2 was about 13.5%,
which was higher than the average elongation of about 11% for Alloy
7. Alloys 8 and 10 included about 0.090 to 0.110 wt % Mn, which may
form higher amount of constituent AlFeMnSi particles that may
result in grain refinement and higher elongation than Alloy 7.
[0161] Alloy 9 had elongations ranging from 9% to 12%, about the
same as Alloys 1 and 7. Alloy 11 had elongations ranging from 13%
to 15.5%, which were higher than that of Alloys 1 and 7, but were
similar to Alloys 8 and 10. The Mg contents of Alloys 9 and 11 were
different from Alloy 10. The Mg contents of Alloys 9 and 11 were
both higher than Alloy 8. Also, the Si contents of Alloys 9 and 11
were lower than Alloys 8 and 10. It seemed that Mg did not affect
elongations of the alloys, while lower Si may increase elongation
of Alloys 9 and 11 to be comparable to that of Alloys 8 and 10,
which had higher elongations due to addition of about 0.090 to
0.110 wt % Mn.
[0162] Alloy 7 had the desirable anodization color b* and was used
as a reference for comparing anodization color b* changes due to
changes in elemental composition.
[0163] FIG. 17 illustrates anodization color b* change (.DELTA.b*)
relative to Alloy 7 for Alloys 8-11 in accordance with embodiments
of the disclosure. As shown in FIG. 17, Alloy 1 had .DELTA.b*of
about -0.2, or b* lower than Alloy 7. Alloy 1 included more Mg than
Alloy 7, which seemed to reduce b*.
[0164] Also, Alloy 8 had .DELTA.b*of about 0.2, or b* 0.2 higher
than Alloy 7, while Alloy 10 had .DELTA.b*of about 0.25, or b* 0.25
higher than Alloy 7. Alloys 8 and 10 included more Mn than Alloy 7,
which seemed to increase b*.
[0165] Also, Alloy 9 had .DELTA.b*of about -0.1, or b* 0.1 lower
than Alloy 7, while Alloy 11 had .DELTA.b*of about -0.4, or b* 0.4
lower than Alloy 7. Alloys 9 and 11 included less Si than Alloy 7,
which seemed to reduce b*.
[0166] Further, Reference Alloy 2 had .DELTA.b*of about -0.4, or b*
lower than Alloy 7.
[0167] Many 6000-series aluminum alloys rely on billet
homogenization to convert an undesirable .beta.-AlFeSi constituent
particles (which are large and plate like), into .alpha.-AlFeSi
particles, which are smaller than the .beta.-AlFeSi constituent
particles. Experiments showed that compositions had a strong
influence on conversion of 3-AlFeSi to .alpha.-AlFeSi or .beta. to
a conversion during homogenization. More .beta. to a conversion
would result in better cosmetic appeal of the alloy.
[0168] Alloys were homogenized for the .beta. to a conversion. In
some variations, homogenization was performed at an elevated
temperature (e.g. about 580.degree. C.) for a period of time (e.g.
12 hours).
[0169] The homogenized alloys were also hot extruded to form
extruded parts. In some variations, the extrusion was performed at
an elevated temperature. The extruder typically heats up the alloy
billet to about 500.degree. C. before extrusion. Then, the
extrusion deformation would further heat up the alloy, and then the
extrusion comes out of the die at about 545.degree. C. The extruded
parts were analyzed for microstructure. For example, the extruded
parts were cross-sectioned and polished. Then, scanning electron
microscopy (SEM) images were taken for the polished cross-sectioned
parts to reveal microstructure and to analyze elemental
compositions by using energy dispersive spectroscopy (EDS). The
particle sizes were then determined.
[0170] FIG. 18 illustrates average diameters of AlFe(Mn)Si
particles for Alloys 1 and 7-11 in accordance with embodiments of
the disclosure. In FIG. 18, B represents "as-cast billet", H
represents homogenized billet, and E represents extrusion. As shown
FIG. 18, Alloys 1 and 7 had average AlFeSi diameters of about 6
.mu.m after extrusion, while Alloys 8 and 10 with Mn 0.090 to 0.110
wt % had average AlFeSi diameters of about 4 .mu.m after extrusion,
which were smaller than Alloys 1 and 7 with Mn 0.015 to 0.025 wt %.
Also, Alloys 9 and 11 had average AlFeSi diameters of about 5 .mu.m
after extrusion, which were smaller than Alloys 1 and 7, likely
associated with lower Si in Alloys 9 and 11 than Alloys 1 and 7.
Also, the percentage or conversion of the .alpha.-AlFe(Mn)Si after
homogenization was 3.8% for Alloy 1 and 13.8% for Alloy 7 (after
extrusion), but was about 90.5% for Alloy 8, 100% for Alloy 10
(after extrusion). The percentage or conversion of the
.alpha.-AlFeSi after homogenization was 96.7% for Alloy 9 and 95.8%
for Alloy 11. The bracket for Mn in .alpha.-AlFe(Mn)Si means that
Mn is optional.
[0171] Alloys 8-11 were extruded by using the extrusion process
similar to Alloy 1, but different from Alloys 2-7. Alloy 1.8-11
were extruded with the same setup as Alloys 2-7, including same
billet diameters, extrusion press, and set of extrusion dies.
However, some extrusion parameters were adjusted (e.g. temperature,
and speed) in order to extrusion higher Mg alloys (e.g. Alloys 1
and 7).
[0172] Table 4 lists the average diameters of AlFeSi particles for
Alloys 1 and 7-11 in extrusion. As shown in Table 4, Alloy 1 had
6.4 .mu.m, Alloy 7 had 5.4 to 6.3 .mu.m. Also, Alloy 8 had 3.9
.mu.m and Alloy 10 had 3.6 .mu.m. Alloys 8 and 10 with small
addition of Mn had smaller average diameters than Alloys 1 and 7.
Further, Alloy 9 had 5.3 .mu.m and Alloy 11 had 5.3 .mu.m. Alloys 9
and 11 with reduced Si content had smaller average diameters than
Alloys 1 and 7.
TABLE-US-00004 TABLE 4 Average Diameters of AlFeSi Particles of
Alloys 1 and 7-11 in Extrusion Average Diameters Alloys (.mu.m)
Alloy 1 6.4 Alloy 7 5.4 to 6.3 Alloy 8 3.9 Alloy 9 5.3 Alloy 10 3.6
Alloy 11 5.3
[0173] Alloys 1 and 7 had larger average AlFeSi diameters than
Alloys 8-11, which suggested low .beta.-AlFeSi to
.alpha.-AlFe(Mn)Si conversion, resulting in undesirable large
.beta.-AlFeSi particles in final extrusion. Alloys 1 and 7 included
higher Si than Reference Alloy 2 and comparable Mn to Reference
Alloy 2,
[0174] The microstructure was further analyzed and the phases of
the AlFeSi particles were determined to be .beta.-AlFeSi or
.alpha.-AlFeSi. Surprisingly, a high conversion of .beta.-AlFeSi to
.alpha.-AlFeSi was observed for Alloy 10 with a small addition of
Mn (0.090 to 0.110 wt % Mn). Without the small addition of Mn (e.g.
0.015 to 0.025 wt % Mn), a low conversion of .beta.-AlFeSi to
.alpha.-AlFeSi was observed for Alloy 7.
[0175] FIG. 19 illustrates a SEM image of the microstructure of
Alloy 7 after extrusion in accordance with embodiments of the
disclosure. As shown in FIG. 19, Alloy 7 revealed a low conversion
of .beta. to .alpha.. After homogenization and extrusion, the alloy
included mostly large .beta.-AlFeSi particles 1902 (light color
particles), which were plate like.
[0176] FIG. 20 illustrates a SEM image of the microstructure of
Alloy 10 after extrusion in accordance with embodiments of the
disclosure. As shown in FIG. 20, Alloy 10 included
.alpha.-AlFe(Mn)Si particles 2002 (light color particles), which
were smaller than the .beta.-AlFeSi particles 1902 (light color
particles) for Alloy 7. This suggests that Alloy 10 revealed a high
conversion of .beta.-AlFeSi particles to .alpha.-AlFe(Mn)Si
particles. The high conversion was surprisingly caused by the
addition of small amounts of Mn in Alloy 10 (e.g. 0.090 to 0.110 wt
% Mn). Without this small amounts of Mn (e.g. 0.015 to 0.025 wt %
Mn), Alloy 7 did not have such a high conversion of .beta.-AlFeSi
particles to .alpha.-AlFeSi particles, instead a low conversion of
.beta.-AlFeSi particles to .alpha.-AlFeSi particles.
[0177] In some variations, the low .beta. to a conversion is less
than 20%. In some variations, the low .beta. to a conversion is
less than 15%. In some variations, the low .beta. to .alpha.
conversion is less than 10%. In some variations, the low .beta. to
a conversion is less than 5%.
[0178] In some variations, the high .beta. to a conversion is at
least 70%. In some variations, the high .beta. to .alpha.
conversion is at least 75%. In some variations, the high .beta. to
a conversion is at least 80%. In some variations, the high .beta.
to a conversion is at least 85%. In some variations, the high
.beta. to a conversion is at least 90%. In some variations, the
high .beta. to a conversion is at least 95%.
[0179] With higher Mn than Reference Alloy 2, Alloys 8 and 10
achieved high .beta. to a conversion after homogenization,
resulting in much smaller .alpha.-AlFeSi particles. The .beta. to a
conversion was associated with higher Mn, as evidenced by the
smaller average AlFeSi diameters.
[0180] Also, with slightly higher Si than Reference Alloy 2, but
lower Si than Alloys 8 and 10, Alloys 9 and 11 achieved most .beta.
to a conversion after homogenization, resulting in much smaller
.alpha.-AlFeSi particles. The .beta. to a conversion was associated
with lower Si, as evidenced by the smaller average AlFeSi
diameters.
[0181] FIG. 21 illustrates a SEM image of the microstructure of
Alloy 9 after extrusion in accordance with embodiments of the
disclosure. As shown in FIG. 21, Alloy 9 included .alpha.-AlFeSi
particles 2102 (light color particles), which were smaller than the
.beta.-AlFeSi particles 1902 (light color particles) for Alloy 7.
This suggests that Alloy 9 revealed a high conversion of
.beta.-AlFeSi particles to smaller .alpha.-AlFeSi particles. The
high conversion was surprisingly caused by the lower Si in Alloy 9
(e.g. 0.57 to 0.63 wt % Si). Without this lower amounts of Si,
Alloy 7 (0.72 to 0.78 wt % Si) did not have such a high conversion
of .beta.-AlFeSi particles to .alpha.-AlFeSi particles, instead a
low conversion of .beta.-AlFeSi particles to .alpha.-AlFeSi
particles.
[0182] As shown above, the elemental effects on properties have
been evaluated for Alloys 8-11. Alloy compositions included 0.55 to
0.75 wt % Si, 0.75 to 0.90 wt % Mg, 0.02 to 0.11 wt % Mn. Table 5
summarizes the effects of the elemental composition of Si, Mg, and
Mg on properties and processability of the alloys. As shown in
Table 5, when Si increases, the yield strength and tensile
strengths would increase, while elongation would decrease with Si
content. When Si content becomes lower, constituent AlFeSi particle
size can be reduced, and lower anodization color b* would be
obtained.
[0183] Turning to Mn, when Mn increases, the yield strength and
tensile strength as well as elongation increase, and smaller
constituent AlFe(Mn)Si particle size were obtained. Lower
anodization color b* would be obtained when Mn decreases.
[0184] Mg was found to provide concurrent strengthening and b*
reduction. Mg can increase the extrusion flow stress, for example,
an estimated 10% increase with every 0.1 wt % addition of Mg. As
shown in Table 5, the yield strength and tensile strength of the
alloy increase with Mg. Lower anodization color b* would be
obtained for the alloy can be obtained with higher Mg.
TABLE-US-00005 TABLE 5 Effects of Compositions Si, Mn, and Mg on
Properties and Processability of Alloys Higher Smaller Yield
Constituent and AlFeSi Lower Tensile Higher Particle Anodization
Strengths Elongation Size color b* Processability Si Higher Si
Lower Si Lower Si Lower Si n/a Mn Higher Mn Higher Mn Higher Mn
Lower Mn n/a Mg Higher Mg n/a n/a Higher Mg Lower Mg
[0185] It will be appreciated by those skilled in the art that
other processing including sheet forming process can also be used
for the disclosed alloys.
[0186] For some applications, the alloys may be tuned with a
particular combination of properties, such as high strengths and
ductility, and easy extrusion.
[0187] For some applications, the alloys may be tuned in
compositions to have with a particular combination of properties,
such as a desirable color, microstructure, cosmetic appeals after
anodization, good strengths, good ductility, and good
extrusion.
Example 3
[0188] Table 6 lists the compositions of Alloys 12-15.
TABLE-US-00006 TABLE 6 Composition in wt % for Various Al Alloys
Alloy 12 Alloy 13 Alloy 14 Alloy 15 Mg/Si 1.04 1.09 1.04 1.09 Ratio
Mg 0.78 0.82 0.78 0.82 Si 0.75 0.75 0.75 0.75 Fe 0.17 0.17 0.17
0.17 Mn 0.035 to 0.035 to 0.065 to 0.065 to 0.045 0.045 0.075 0.075
Cr Less Less Less Less than 0.10 than 0.10 than 0.10 than 0.10 Cu
0.015 0.015 0.015 0.015 Ni 0 to 0 to 0 to 0 to 0.01 0.01 0.01 0.01
Zn 0 to 0 to 0 to 0 to 0.20 0.20 0.20 0.20 Ti 0 to 0 to 0 to 0 to
0.10 0.10 0.10 0.10
[0189] As shown in Table 6, Alloys 11-15 had the same Si content,
i.e. 0.75 wt %. Alloys 12 and 13 had 0.035-0.045 wt % Mn, and
Alloys 14 and 15 had 0.035-0.045 wt % Mn.
[0190] The disclosed aluminum alloys and methods can be used in the
fabrication of electronic devices. An electronic device herein can
refer to any electronic device known in the art. For example, such
devices can include wearable devices such as a watch (e.g., an
AppleWatch.RTM.). Devices can also be a telephone such a mobile
phone (e.g., an iPhone.RTM.) a land-line phone, or any
communication device (e.g., an electronic email sending/receiving
device). The alloys can be a part of a display, such as a digital
display, a TV monitor, an electronic-book reader, a portable
web-browser (e.g., iPad.RTM.), and a computer monitor. The alloys
can also be an entertainment device, including a portable DVD
player, conventional DVD player, Blue-Ray disk player, video game
console, music player, such as a portable music player (e.g.,
iPod.RTM.), etc. The alloys can also be a part of a device that
provides control, such as controlling the streaming of images,
videos, sounds (e.g., Apple TV.RTM.), or can be a remote control
for an electronic device. The alloys can be a part of a computer or
its accessories, such as the hard drive tower housing or casing for
iPad, MacBook, or Mac Mini.
[0191] Any ranges cited herein are inclusive. The terms
"substantially" and "about" used throughout this Specification are
used to describe and account for small fluctuations. For example,
they can refer to less than or equal to .+-.5%, such as less than
or equal to .+-.2%, such as less than or equal to .+-.1%, such as
less than or equal to .+-.0.5%, such as less than or equal to
.+-.0.2%, such as less than or equal to .+-.0.1%, such as less than
or equal to .+-.0.05%.
[0192] Having described several embodiments, it will be recognized
by those skilled in the art that various modifications, alternative
constructions, and equivalents may be used without departing from
the spirit of the invention. Additionally, a number of well-known
processes and elements have not been described in order to avoid
unnecessarily obscuring the invention. Accordingly, the above
description should not be taken as limiting the scope of the
invention.
[0193] Those skilled in the art will appreciate that the disclosed
embodiments teach by way of example and not by limitation.
Therefore, the matter contained in the above description or shown
in the accompanying drawings should be interpreted as illustrative
and not in a limiting sense. The following claims are intended to
cover all generic and specific features described herein, as well
as all statements of the scope of the method and system, which, as
a matter of language, might be said to fall therebetween.
* * * * *