Methods for relieving stress in an additively manufactured alloy body

Patent metadata

Field	Value
Publication number	US-2016228950-A1
Application number	US-201615005825-A
Country	US
Kind code	A1
Filing date	Jan 25, 2016
Priority date	Feb 5, 2015
Publication date	Aug 11, 2016
Grant date	—

Abstract

Methods for producing additively manufactured products are disclosed. In one embodiment, a method comprises using additive manufacturing to produce an aluminum alloy body, and, after the using step (a), cold working at least a portion of the aluminum alloy body, thereby relieving stress.

First claim

What is claimed is:

1 . A method comprising:
(a) using additive manufacturing to produce an aluminum alloy body;
wherein, due at least in part to the using additive manufacturing step (a), the aluminum alloy body realizes a first amount of residual stress;
(b) after the using step (a), cold working at least a portion of the aluminum alloy body, thereby relieving stress in cold worked portions of the aluminum alloy body;
wherein the cold working comprises cold deforming the aluminum alloy body by at least 0.1%;
wherein, due at least in part to the cold working step (b), at least some of the cold worked portions realize a second amount of residual stress; and
wherein the second amount of residual stress is lower than the first amount of residual stress.

2 . The method of claim 1 , wherein the aluminum alloy body is an aluminum alloy selected from the group consisting of: a 1xxx aluminum alloy, a 2xxx aluminum alloy, a 3xxx aluminum alloy, a 4xxx aluminum alloy, a 5xxx aluminum alloy, a 6xxx aluminum alloy, a 7xxx aluminum alloy, and an 8xxx aluminum alloy.

3 . The method of claim 1 , wherein the aluminum alloy body is a 4xxx series aluminum alloy.

4 . The method of claim 3 , wherein the aluminum alloy body is a 4046 aluminum alloy.

5 . The method of claim 1 , wherein the cold working step (b) comprises at least one of compressing, stretching, and combinations thereof.

6 . The method of claim 1 , wherein the cold working step (b) comprises cold deforming all parts of the aluminum alloy body by at least 0.1%.

7 . The method of claim 1 , wherein the cold working step (b) comprises cold deforming by not greater than 25%.

8 . The method of claim 7 , wherein during the cold working step, the aluminum alloy body is at a temperature of not greater than 250° F.

9 . The method of claim 1 , wherein, due at least in part to the cold working step (b), the aluminum alloy body realizes increased tensile yield strength as compared to a similar aluminum alloy body which has been annealed to relieve residual stress.

10 . The method of claim 1 , comprising:
performing the using additive manufacturing step (a) and then performing the cold working step (b), wherein the method is free of any solution heat treatment step between steps (a) and (b).

11 . The method of claim 10 , wherein the method is free of any solution heat treating step after step (b).

12 . The method of any claim 10 , wherein, after the using step, aluminum alloy body is maintained below 450° F.

13 . The method of claim 1 , comprising:
artificially aging the aluminum alloy body at a temperature of from 150° F. to 450° F.

14 . A method consisting of:
(a) using additive manufacturing to produce an aluminum alloy body;
wherein, due at least in part to the using additive manufacturing step (a), the aluminum alloy body realizes a first amount of residual stress;
(b) after the using step (a), cold working the aluminum alloy body, thereby relieving stress in the aluminum alloy body;
wherein the cold working comprises cold deforming the aluminum alloy body by at least 0.1%;
wherein due at least in part to the cold working step (b), the aluminum alloy body realizes a second amount of residual stress; and
wherein the second amount of residual stress is lower than the first amount of residual stress.

Assignees

• Alcoa Inc

Inventors

• Bodily Brandon H
• Bush Dustin M

Classifications

• B22F10/64

  by thermal means (control of energy beam parameters for post heating B22F10/364) · CPC title

• B22F10/18

  by mixing binder with metal in filament form, e.g. fused filament fabrication [FFF] · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• C22F1/04

  of aluminium or alloys based thereon · CPC title