U.S. patent application number 13/573378 was filed with the patent office on 2015-09-10 for high strength al-cu-mg-ag-si alloy for cast product structural applications.
The applicant listed for this patent is Alex Cho. Invention is credited to Alex Cho.
Application Number | 20150252454 13/573378 |
Document ID | / |
Family ID | 54016792 |
Filed Date | 2015-09-10 |
United States Patent
Application |
20150252454 |
Kind Code |
A1 |
Cho; Alex |
September 10, 2015 |
High strength al-cu-mg-ag-si alloy for cast product structural
applications
Abstract
The present invention relates generally to
aluminum-copper-magnesium based alloys and products, and more
particularly to aluminum-copper-magnesium-Silver-Silicon based
alloys and products particularly suitable for aircraft structural
applications and military vehicle structural applications requiring
very high strength and ductility.
Inventors: |
Cho; Alex; (Lexington,
KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cho; Alex |
Lexington |
KY |
US |
|
|
Family ID: |
54016792 |
Appl. No.: |
13/573378 |
Filed: |
September 12, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61573782 |
Sep 12, 2011 |
|
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|
61626790 |
Oct 3, 2011 |
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Current U.S.
Class: |
420/535 ;
148/417 |
Current CPC
Class: |
C22C 21/16 20130101;
C22C 21/14 20130101; C22C 21/12 20130101 |
International
Class: |
C22C 21/16 20060101
C22C021/16; C22C 21/14 20060101 C22C021/14; C22C 21/12 20060101
C22C021/12 |
Goverment Interests
[0002] This application is part of a government project. The
research leading to this invention was supported by a Grant Number
W911NF-07-2-0073 from the U.S. ARMY. The United States Government
retains certain rights in this invention.
Claims
1. Aluminum based alloy cast product with alloy chemistries
comprising from about 4.0-6.0 wt. % copper, from about 0.1-1.8 wt.
% magnesium, from about 0.0-0.8 wt. % silver, from about 0.0-0.8
wt. % manganese, from about 0.1-1.2 silicon, and from about
0.0-0.12 titanium and the balance being aluminum and incidental
elements and impurities.
2. The alloy of claim 1, wherein said incidental element and
impurities can includes iron.
3. The alloy of claim 1, further comprising one or more dispersoid
forming elements selected from the group consisting of chromium,
zirconium, scandium and vanadium and combinations thereof.
4. The alloy of claim 1, further comprising chromium in an amount
of up to 0.8 wt. %, scandium in an amount up to 0.8 wt. %, and
vanadium in an amount of up to 0.2 wt. % either in addition to, or
instead of titanium.
5. The alloy of claim 1 exhibit very high strength when the alloy
is processed via solution heat treatment and age strengthening to
T6 temper product for engineering structural applications having
surprisingly high strength (i.e., no cold work or very low amount
of cold work prior to final age strengthening step on the product
of water quenched after solution heat treatment)
6. The alloy of claim 1 is suitable for T8 temper application with
even more pronounced high strength capability for engineering
structural applications.
Description
CROSS REFERENCES TO OTHER APPLICATIONS
[0001] This application claims priority from U.S. Provisional
Application Ser. No. 61/573,782 filed on Sep. 12, 2011 and U.S.
Provisional Application Ser. No. 61/626,790 filed on Oct. 3, 2011
bothl of which are incorporated by reference herein in their
entirety. Reference to documents made in the specification is
intended to result in such patents or literature cited are
expressly incorporated herein by reference, including any patents
or other literature references cited within such documents as if
fully set forth in this specification.
FIELD OF INVENTION
[0003] The present invention relates generally to
aluminum-copper-magnesium based alloys and products, and more
particularly to aluminum-copper-magnesium-silver-silicon based
alloys and products particularly suitable as cast product for
aircraft structural applications and military vehicle structural
applications requiring very high strength and ductility.
BACKGROUND INFORMATION OF THE INVENTION
Description of Related Art
[0004] Aluminum alloys containing copper, magnesium and silver are
known in the art.
[0005] U.S. Pat. No. 4,772,342 describes a wrought
aluminum-copper-magnesium-silver alloy including copper in the
amount of 5.7 weight (wt.) percent (%), magnesium in an amount of
0.3-0.8 wt. %, silver in an amount of 0.2-1 wt. %, manganese in an
amount of 0.3-1.0 wt. %, zirconium in an amount of 0.1-0.25 wt. %,
vanadium in an amount of 0.05-0.15 wt. %, silicon less than 0.10
wt. %, and the balance aluminum.
[0006] U.S. Pat. No. 5,376,192 discloses a wrought aluminum alloy
comprising about 2.5-5.5 wt. % copper, about 0.10-2.3 wt. %
magnesium, about 0.1-1.0 wt. % silver, up to 0.05wt. % titanium and
the balance aluminum, in which the amount of copper and magnesium
together is maintained at less than the solid solubility limit for
copper and magnesium in aluminum.
[0007] U.S. Pat. Nos. 5,630,889, 5,665,306, 5,800,927, and
5,879,475 disclose substantially vanadium-free aluminum-based
alloys including about 4.85-5.3 wt. % copper, about 0.5-1 wt. %
magnesium, about 0.4-0.8 wt. % manganese, about 0.2-0.8 wt. %
silver, up to about 0.25 wt. % zirconium, up to about 0.1 wt. %
silicon, and up to 0.1 wt. % iron, the balance aluminum, incidental
elements and impurities. The alloy can be produced for use in
extruded, rolled or forged products, and in a preferred embodiment,
the alloy contains a Zr level of about 0.15 wt. %.
SUMMARY OF THE INVENTION
[0008] An object of the present invention was to provide a high
strength, high ductility alloy, comprising copper, magnesium,
silver, manganese, silicon and optionally dispersoid forming
elements.
[0009] In accordance with the present invention, there is provided
an aluminum-copper alloy comprising about 4.5-6.8 wt. % copper,
0.1-1.8 wt. % magnesium, 0.1-0.8 wt. % silver, 0.0-1.2 wt. %
manganese, 0.25-1.2 wt. % silicon, the balance being aluminum and
incidental elements and impurities such as, not limited to, iron up
to 0.5%, zinc up to 0.5% and nickel up to 0.5 wt. %. Optionally one
or more dispersoid forming elements selected from the group
consisting of Titanium, Zirconium, Chromium, Scandium and Vanadium
may be added in an amount up to 0.5 wt. % for titanium, 0.25 wt. %
for zirconium, 0.5 wt. % for Cr, 0.5 wt. %, 0.8 wt. % for Sc, and
0.2 wt. % for V.
[0010] The inventive alloy can be manufactured and/or treated in
any desired manner, such as by forming an extruded, rolled, or
forged product. The present invention is further directed to
methods for the manufacture and use of alloys as well as to
products comprising alloys.
[0011] Additional objects, features, and advantages of the
invention will be set forth in the description which follows, and
in part, will be obvious from the description, or may he learned by
practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A better understanding of the present invention will be had
upon reference to the following description in conjunction with the
accompanying drawings in which like numerals refer to like parts
throughout the several views and wherein:
[0013] FIG. 1. Photograph of the Constrained Rod Casting for alloyl
1238 showing no cracks;
[0014] FIG. 2. Photograph of the Constrained Rod Casting for alloy
11239 showing no cracks; and
[0015] FIG. 3. Photograph of the Constrained Rod Casting for alloy
11191 showing no cracks.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0016] The high strength AL--CU--MG--AG--SI ALLOY for structural
applications comprises a, high ductility alloy, comprising copper,
magnesium, silver, manganese, silicon and optionally dispersoid
forming elements.
[0017] One preferred embodiment of an aluminum-copper alloy
comprises about 4.5-6.8 wt. % copper, 0.1-1.8 wt. % magnesium,
0.1-0.8 wt. % silver, 0.0-1.2 wt. % manganese, 0.25-1.2 wt. %
silicon, the balance being aluminum and incidental elements and
impurities such as, not limited to, iron up to 0.5%, zinc up to
0.5% and nickel up to 0.5 wt. %. Optionally one or more dispersoid
forming elements selected from the group consisting of Titanium,
Zirconium, Chromium, Scandium and Vanadium may be added in an
amount of up to 0.5% for titanium, 0.25% for zirconium, 0.5 wt. %
for Cr, 1.0 wt. %. 0.8 wt. % for Sc, and 0.2 wt. % for V.
[0018] The following examples describe preferred embodiments of the
invention. Other embodiments within the scope of the claims herein
will be apparent to one skilled in the art from consideration of
the specification or practice of the invention as disclosed herein.
It is intended that the specification, together with the examples,
be considered exemplary only, with the scope and spirit of the
invention being indicated by the claims which follow the examples.
In the examples all percentages are given on a weight basis unless
otherwise indicated.
[0019] Reference to documents made in the specification is intended
to result in such patents or literature cited are expressly
incorporated herein by reference, including any patents or other
literature references cited within such documents as if fully set
forth in this specification.
[0020] These and other objects of the present invention will be
more fully understood from the following description of the
invention.
EXAMPLES
Invented Alloys
[0021] The Laboratory scale ingots were cast with 2 inch thick by 5
inch wide by 15 inch long permanent mold for invented alloys (Alloy
no. 11238, 11239 and 11191) and the baseline alloy, B206. [0022]
The alloy chemistries are shown in the TABLE 1:
TABLE-US-00001 [0022] TABLE 1 CHEMISTRY OF THE INVENTED ALLOYS and
B206 (baseline alloy) (all chemistries are in wt. %) Alloy No Cu Mg
Mn Ag Si Ti Zr Fe No. 11238 4.6 0.3 0.25 0.35 0.3 0.05 0.02 0.05
No. 11239 4.8 0.3 0.25 0.36 0.3 0.05 0.02 0.04 No. 11191 5.0 0.35
0.35 0.35 0.28 0.05 0.01 0.05 B206 (baseline) 4.6 0.25 0.4 -- 0.10
0.01 -- 0.06
Mechanical Properties
[0023] These ingots were homogenized at a temperature of 950 degree
F. for 24 hours. These ingot were solution heat treated at 950
degree F. for 2 hours, followed by cold water quench. The water
quenched product were age hardened for 4 hours at 350 deg F. in T6
temper condition The mechanical property test results from the peak
strength aged material are shown in Table 2:
TABLE-US-00002 TABLE 2 TENSILE PROPERTIES OF THE INVENTED ALLOYS
WITH THE BASELINE ALLOY B206. (0% cold work prior to age hardening
process) Test 0.2% Yield Ultimate Elonga- ALLOY NO Direction Stress
Tensile Strength tion No. 11238 Longitudinal 64.8 ksi 71.7 ksi 7.0%
No. 11239 Longitudinal 66.2 ksi 70.7 ksi 4.3% No. 11191
Longitudinal 66.2 ksi 70.7 ksi 3.8% B206(Baseline) Longitudinal
51.3 ksi 59.6 ksi 5.1%
[0024] The comparison of the longitudinal direction tensile
properties of the invented alloys, No 11238, No. 11239 and No.
11191 to the baseline alloy B206 in Table 2 demonstrated the high
strength advantage of the inventive alloys with better or
comparable ductility in -T6 temper condition.
Castability of the Invented Alloys
[0025] High strength alloys based on Al--Cu--Mg alloy system is
known for their poor castability. However, the most surprising
benefit of these invented alloys for cast product applications is
their excellent castability showing high level of resistance
against hot tearing during casting. To demonstrate the superior
castability of these alloys, hot tearing tear resistance of these
alloys were evaluated by utilizing "Constrained Rod Casting Mold"
described in the excellent work published by Kamga et al. ("Hot
Tearing of Aluminum-Copper B206 alloys with Iron and Silicon
additions" Materials Science and Engineering. A527 (2010) pp
7413-7423). The photographs of the CRC Mold casting of these
invented alloys are shown FIG. 1, FIG. 2 and FIG. 3 below
demonstrating no cracks at all after casting by following the exact
testing procedure described in the published work.
[0026] The foregoing detailed description is given primarily for
clear understanding of the benefits of the new alloy compositions
for cast product application, having optimum amount of alloying
element of copper, magnesium, silver and silicone with dispersoid
forming elements and incidental impurities.
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