Method for producing void-free additively manufactured components

Patent metadata

Field	Value
Publication number	US-9950467-B2
Application number	US-201514695200-A
Country	US
Kind code	B2
Filing date	Apr 24, 2015
Priority date	May 8, 2014
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A method of additive manufacturing of a component includes cutting a plurality of sheets, each sheet corresponding to a respective cross-section of the component, tack welding the sheets to one another to form a stack, arranging the stack in a mold, and spark plasma sintering the tack-welded stack of sheets to reduce vacancies and dislocations between adjacent sheets of the stack.

First claim

The invention claimed is:

1. A method for additive manufacturing a component, the method comprising:
(a) cutting a plurality of sheets, each sheet corresponding to a respective cross-section of the component;
(b) tack welding the sheets to one another to form a stack;
(c) arranging the stack in a mold; and
(d) spark plasma sintering the tack-welded stack of sheets to reduce vacancies and dislocations between adjacent sheets of the stack.

2. The method of claim 1 , wherein arranging the stack in the mold comprises positioning the stack in a ring mold.

3. The method of claim 1 , wherein arranging the stack in the mold comprises applying pressure to compress the sheets of the stack together.

4. The method of claim 3 , wherein applying pressure to compress the sheets of the stack together comprises:
arranging a first platen to apply pressure to one side of the stack and;
arranging a second platen to apply pressure to an opposite side of the stack.

5. The method of claim 4 , wherein spark plasma sintering comprises:
arranging a first electrode in electrical communication with the one side of the stack;
arranging a second electrode in electrical communication with the opposite side of the stack; and
applying a sufficient electrical potential between the first electrode and the second electrode to heat the stack.

6. The method of claim 5 , wherein the first electrode comprises:
a copper layer;
a brass layer arranged between the copper layer and the stack; and
a graphite layer arranged between the brass layer and the stack.

7. The method of claim 1 , further comprising heating the stack prior to spark plasma sintering.

8. The method of claim 1 , further comprising applying a magnetic field in the stack during spark plasma sintering.

9. The method of claim 8 , wherein applying a magnetic field in the stack comprises driving current in an induction heating coil arranged around the mold.

10. The method of claim 1 , wherein the mold is configured to circumscribe the stack.

11. The method of claim 1 , further comprising packing a powder material between the mold and the stack.

12. The method of claim 11 , wherein the powder material is a conductive powder.

13. The method of claim 12 , wherein the powder material is a graphite powder.

14. The method of claim 1 , wherein cutting the plurality of sheets comprises cutting a sheet material using a radiation source.

15. The method of claim 14 , wherein the radiation source is a laser.

16. The method of claim 1 , wherein spark plasma sintering includes inducing a quasi-viscous state in the stack.

Assignees

• United Technologies Corp

Inventors

• Mironets Sergey

Classifications

• B29C64/147

  using sheet material, e.g. laminated object manufacturing [LOM] or laminating sheet material precut to local cross sections of the 3D object · CPC title

• B23P17/00

  Metal-working operations, not covered by a single other subclass or another group in this subclass · CPC title

• B23P2700/12

  Laminated parts · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title

• B22F2003/1051

  by electric discharge · CPC title