Surface improvement of additively manufactured articles produced with aluminum alloys

Patent metadata

Field	Value
Publication number	US-2017129060-A1
Application number	US-201514933154-A
Country	US
Kind code	A1
Filing date	Nov 5, 2015
Priority date	Nov 5, 2015
Publication date	May 11, 2017
Grant date	—

Abstract

A method for improving the surface of an aluminum alloy article includes manufacturing the aluminum alloy article using an additive manufacturing technique, wherein the article as-manufactured includes one or more of cracks, roughness, or porosity at a surface of the article; coating the surface of the aluminum alloy article with a diffusion element, the diffusion element being capable of diffusing at least 0.2 mils into the article; heating the aluminum alloy article coated with the diffusion element to cause the diffusion element to diffuse the at least 0.2 mils into the article, thereby forming a diffusion layer of at least 0.2 mils in thickness comprising both aluminum alloy and diffusion element; and removing the diffusion layer from the aluminum alloy article, whereby upon the removing, a resulting improved surface of the article comprises fewer or smaller cracks, reduced roughness, or reduced porosity.

First claim

What is claimed is:

1 . A method for improving the surface of an aluminum alloy article comprising:
manufacturing the aluminum alloy article using an additive manufacturing technique, wherein the article as-manufactured comprises one or more of cracks, roughness, or porosity at a surface of the article; coating the surface of the aluminum alloy article with an encapsulating element, which may or may not also be a diffusion element, to facilitate HIP response; coating the surface of the aluminum alloy article with a diffusion element, the diffusion element being capable of diffusing at least 0.2 mils into the article; heating the aluminum alloy article coated with the diffusion element to cause the diffusion element to diffuse the at least 0.2 mils into the article, thereby forming a diffusion layer of at least 0.2 mils in thickness comprising both aluminum alloy and diffusion element; removing the diffusion layer from the aluminum alloy article, whereby upon the removing, a resulting improved surface of the article comprises fewer or smaller cracks, reduced roughness, or reduced porosity.

2 . The method of claim 1 , wherein the aluminum alloy article comprises an aluminum alloy selected from the group consisting of: cast alloys, wrought alloys, derivatives of said cast or wrought alloys having slightly modified composition for improved additive manufacturing, and non-conventional alloys, such as those known as rapidly solidified aluminum powders.

3 . The method of claim 1 , wherein the additive manufacturing technique is selected from the group consisting of: direct metal laser sintering, direct metal laser fusion, electron beam melting, and selective laser sintering.

4 . The method of claim 1 , wherein the diffusion element comprises zinc.

5 . The method of claim 1 , wherein the diffusion element comprises tin.

6 . The method of claim 1 , wherein the diffusion and/or encapsulating element is selected from the group consisting of: electroless silver, gold, copper, and nickel.

7 . The method of claim 1 , wherein coating the surface comprises an electroless plating process or wherein coating the surface comprises an electrolytic plating process where feasible.

8 . The method of claim 7 , wherein coating the surface comprises a zincate plating process.

9 . The method of claim 1 , wherein the diffusion element diffuses at least 1 mil into the article.

10 . The method of claim 1 , further comprising repeating the steps of coating, heating, and removing an additional one or more times.

11 . The method of claim 11 , wherein coating with the encapsulating occurs after the removing step.

12 . The method of claim 1 , further comprising hot isostatic pressing the article.

13 . The method of claim 1 , wherein hot isostatic pressing occurs after the removing step.

14 . The method of claim 1 , wherein the aluminum alloy article is a component of a gas turbine engine.

Assignees

• Honeywell Int Inc

Inventors

• Szuromi Andy
• Starr Steve
• Godfrey Donald G
• Morris Mark C

Classifications

• B23P6/045 Primary

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• B22F10/25

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• B22F12/49

  Scanners · CPC title

• B22F10/66

  by mechanical means · CPC title

• B22F12/63

  Rollers · CPC title