Heat treatable aluminum alloys having magnesium and zinc and methods for producing the same

Patent metadata

Field	Value
Publication number	US-9587298-B2
Application number	US-201313791988-A
Country	US
Kind code	B2
Filing date	Mar 9, 2013
Priority date	Feb 19, 2013
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

New magnesium-zinc aluminum alloy bodies and methods of producing the same are disclosed. The new magnesium-zinc aluminum alloy bodies generally include 3.0-6.0 wt. % magnesium and 2.5-5.0 wt. % zinc, where at least one of the magnesium and the zinc is the predominate alloying element of the aluminum alloy bodies other than aluminum, and wherein (wt. % Mg)/(wt. % Zn) is from 0.6 to 2.40, and may be produced by preparing the aluminum alloy body for post-solutionizing cold work, cold working by at least 25%, and then thermally treating. The new magnesium-zinc aluminum alloy bodies may realize improved strength and other properties.

First claim

What is claimed is:

1. A method comprising:
(a) preparing an aluminum alloy body for post-solutionizing cold working, the aluminum alloy body comprising 3.25-6.0 wt. % magnesium and 2.5-5.0 wt. % zinc, where at least one of the magnesium and the zinc is the predominate alloying element of the aluminum alloy body other than aluminum, and wherein a ratio of wt. % Mg, to wt. % Zn is from 0.6 to 2.40;
(i) wherein the preparing comprises solutionizing by solution heat treating and then quenching the aluminum alloy body, where the quenching reduces the temperature of the aluminum alloy body to a temperature of not greater than 200° F. and a rate of at least 200° F. per second;

(b) after the preparing step, cold working the aluminum alloy body, wherein the cold working induces at least 25% cold work in the aluminum alloy body;
(c) after the cold working step, thermally treating the aluminum alloy body, wherein the thermally treating step comprises:
(i) forming the aluminum alloy body into a predetermined shaped product, wherein, during the forming step, the aluminum alloy body is subjected to a temperature in the range of from at least 150° F. to below the recrystallization temperature of the aluminum alloy body.

2. The method of claim 1 , wherein the thermally treating step comprises:
heating the aluminum alloy body for a time and at a temperature sufficient to achieve a selected condition, wherein the heating step occurs before the forming step.

3. The method of claim 2 , wherein the selected condition is an underaged condition, and wherein the method comprises:
selecting the underaged condition, wherein the selecting step occurs prior to the thermally treating step;
completing the heating step to achieve the underaged condition.

4. The method of claim 3 , comprising
after the completing step, performing the forming step, wherein, after the forming, the predetermined shaped product achieves at least one predetermined property.

5. The method of claim 4 , wherein the at least one predetermined property is a predetermined strength.

6. The method of claim 4 , wherein the at least one predetermined property is a predetermined combination of strength and ductility.

7. The method of claim 5 , wherein the predetermined property is an underaged condition.

8. The method of claim 7 , wherein the underaged condition is within 30% of peak strength.

9. The method of claim 7 , wherein the underaged condition is within 10% of peak strength.

10. The method of claim 1 , wherein the heating step is a first heating step, wherein the thermally treating step comprises:
second heating of the aluminum alloy body, wherein the second heating occurs after the forming step.

11. The method of claim 10 , wherein the second heating comprises heating the aluminum alloy body to achieve a second selected condition.

12. The method of claim 11 , wherein the second selected condition is one of a second predetermined strength, a second predetermined ductility, and a second predetermined combination of strength and ductility.

13. The method of claim 12 , wherein the second predetermined strength is peak strength.

14. The method of claim 12 , wherein the predetermined strength is an overaged strength, wherein the overaged strength is at least 2% lower than the peak strength.

15. The method of claim 1 , wherein, after the forming step (c)(i), the predetermined shaped product realizes higher long-transverse tensile yield strength relative to the long-transverse tensile yield strength of the aluminum alloy body in an as cold worked condition.

16. The method of claim 1 , wherein, after the forming step, the predetermined shaped product is within 10% of peak strength.

17. The method of claim 1 , wherein, after the forming step, the predetermined shaped product is within 5% of peak strength.

18. The method of claim 1 , wherein the cold working comprises cold rolling the aluminum alloy body into a sheet or plate.

19. The method of claim 1 , wherein the aluminum alloy body comprises 3.5-6.0 wt. % magnesium and 2.5-5.0 wt. % zinc, where at least one of the magnesium and the zinc is the predominate alloying element of the aluminum alloy body other than aluminum, and wherein the ratio of wt. % Mg to wt. % Zn is from 0.6 to 2.40.

20. The method of claim 1 , wherein the aluminum alloy body comprises 3.75-6.0 wt. % magnesium and 2.5-5.0 wt. % zinc, where at least one of the magnesium and the zinc is the predominate alloying element of the aluminum alloy body other than aluminum, and wherein the ratio of wt. % Mg to wt. % Zn is from 0.6 to 2.40.

Assignees

• Alcoa Inc
• Arconic Inc

Inventors

• Lin Jen C
• Newman John M
• Sawtell Ralph R
• Kamat Rajeev G
• Boysel Darl G
• Bray Gary H
• Bryant James Daniel
• Connor Brett P
• Greco Mario
• Iasella Gino Norman
• Mcneish David J
• Murtha Shawn J
• Rioja Roberto J
• Sullivan Shawn P

Classifications

• C22C21/06 Primary

  with magnesium as the next major constituent · CPC title

• C22F1/047 Primary

  of alloys with magnesium as the next major constituent · CPC title

• C22C21/10

  with zinc as the next major constituent · CPC title

• C22C21/08

  with silicon · CPC title

• C22F1/053

  of alloys with zinc as the next major constituent · CPC title