Additive manufacturing processing with oxidation

Patent metadata

Field	Value
Publication number	US-2017370005-A1
Application number	US-201615195210-A
Country	US
Kind code	A1
Filing date	Jun 28, 2016
Priority date	Jun 28, 2016
Publication date	Dec 28, 2017
Grant date	—

Abstract

A method includes additively manufacturing an article in an inert environment, removing the article from the inert environment and placing the article in a non-inert environment, allowing at least a portion the article to oxidize in the non-inert environment to form an oxidized layer on a surface of the article, and removing the oxidized layer (e.g., to smooth the surface of the article). The method can further include relieving stress in the article (e.g., via heating the article after additive manufacturing).

First claim

What is claimed is:

1 . A method, comprising:
additively manufacturing an article in an inert environment; removing the article from the inert environment and placing the article in a non-inert environment; allowing at least a portion the article to oxidize in the non-inert environment to form an oxidized layer on a surface of the article; and removing the oxidized layer.

2 . The method of claim 1 , wherein removing the oxidized layer smooths the surface of the article.

3 . The method of claim 1 , further comprising relieving stress in the article.

4 . The article of claim 3 , wherein relieving stress includes heating the article after additive manufacturing.

5 . The method of claim 4 , wherein allowing at least a portion of the article to oxidize is done while heating the article.

6 . The method of claim 1 , including masking a portion of the article to prevent oxidation of the masked portion before allowing at least a portion of the article to oxidize.

7 . The method of claim 1 , wherein allowing at least a portion of the article to oxidize includes controlling at least one of a humidity, air quality, or temperature to control oxidation rate and/or oxidation layer thickness.

8 . The method of claim 7 , wherein allowing at least a portion of the article to oxidize includes preferentially oxidizing a portion of the article by introducing circulation of humidity or oxidizing gas around the article or through a passage of the article to achieve a predetermined oxidation rate or a predetermined oxidation layer thickness.

9 . The method of claim 1 , wherein placing the article in a non-inert environment includes placing the article in at least one of a nitriding environment, a carburizing environment, a sulfurizing environment, a boriding environment, a chloriding environment, or a fluoriding environment.

10 . The method of claim 1 , wherein removing the oxidized layer includes treating the oxidized layer with an ionic liquid.

11 . The method of claim 10 , wherein treating the oxidized layer with an ionic liquid includes treating the oxidized layer with choline chloride.

12 . The method of claim 10 , wherein treating the oxidized layer with an ionic liquid includes electro-polishing to descale the oxidized layer.

13 . The method of claim 1 , further comprising passivating the surface of the article after removing the oxidation layer.

14 . The method of claim 1 , further comprising post processing the article after removing the oxidize layer.

15 . A method of modifying an additively manufactured article, comprising:
forming an oxidation layer on portions of the additively manufactured article; and removing the oxidation layer.

16 . The method of claim 15 , further comprising relieving stress in the additively manufactured article.

17 . The method of claim 15 , further comprising improving surface finish on surfaces of the portions of the additively manufactured article.

18 . The method of claim 15 , further comprising reducing porosity of the portions of the additively manufactured article.

19 . The method of claim 15 , further comprising forming a uniform thickness of the oxidation layer.

20 . The method of claim 15 , further comprising removing material on the portions of the additively manufactured article.

Assignees

• Delavan Inc

Inventors

• Mironets Sergey
• Wentland William L
• Donovan Matthew
• Ocken Thomas J
• Bianco Robert

Classifications

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title

• C23C8/80

  After-treatment · CPC title

• B22F2003/247

  Removing material: carving, cleaning, grinding, hobbing, honing, lapping, polishing, milling, shaving, skiving, turning the surface · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B22F3/24 Primary

  After-treatment of workpieces or articles {(B22F3/1146 takes precedence)} · CPC title