Method for preserving shape of an object during sintering

Patent metadata

Field	Value
Publication number	US-11969794-B2
Application number	US-202017615141-A
Country	US
Kind code	B2
Filing date	May 11, 2020
Priority date	May 30, 2019
Publication date	Apr 30, 2024
Grant date	Apr 30, 2024

Abstract

A method for preserving the shape of an object during sintering includes filling at least one volume defined by a surface of the object with a plurality of balls, sintering the object together with the balls and separating the object from the balls post sintering. The balls have a diameter of 0.5 mm-12 mm.

First claim

What is claimed is:

1. A method for preserving the shape of an object during sintering, the method comprising:
immersing the object in a pool of balls such that said balls engage at least a portion of an outer surface of the object both from below the object and from above the object, wherein the pool of balls is housed in a cage formed with a mesh or grid;
while the object is immersed in the pool, sintering the object together with the balls; and
separating the object from the balls post sintering.

2. The method according to claim 1 , wherein the cage is formed from stainless steel.

3. The method according to claim 1 , wherein the balls are formed with aluminum.

4. The method according to claim 1 , wherein the balls are formed with ceramic material.

5. The method according to claim 4 , wherein the ceramic material is boron nitride or aluminum nitride.

6. The method according to claim 1 , wherein the balls are solid balls.

7. The method according to claim 1 , wherein the balls include an oxide layer.

8. The method according to claim 7 , wherein the balls are treated to increase thickness of the oxide layer.

9. The method according to claim 1 , wherein the balls are spherical in shape.

10. The method according to claim 1 , wherein the balls have a same diameter.

11. The method according to claim 1 , wherein the balls have different diameters.

12. The method according to claim 1 , wherein a first volume defined by the surface of the object is filled with balls having a first diameter and a second volume defined by the surface of the object is filled with balls having a second diameter, wherein the second diameter is other than the first diameter.

13. The method according to claim 1 , wherein a size of the balls is selected based on a size and shape of the object.

14. The method according to claim 1 , wherein the balls have a diameter of 2 mm-6 mm selected so as to allow air flow.

15. The method according to claim 1 , wherein the object is formed by additive manufacturing.

16. The method according to claim 1 , wherein the object is formed with aluminum powder.

17. The method according to claim 1 , wherein said immersing is such that all parts of the object are below an upper surface of the pool of balls.

18. The method according to claim 1 , wherein each ball has a diameter of 0.5 mm-12 mm.

19. A method for preserving the shape of an object during sintering, the method comprising:
filling at least one volume defined by a surface of the object with a plurality of balls, wherein each ball has a diameter of 0.5 mm-12 mm;
sintering the object together with the balls; and
separating the object from the balls post sintering;
wherein the method comprises forming a barrier between the plurality of balls and the surface of the object with inert sand, and wherein said sintering is of the object including said barrier.

20. The method according to claim 19 , comprising placing the object and the inert sand in a bag, wherein said sintering comprises sintering the object in the bag with the inert sand.

21. The method according to claim 20 , wherein the bag is formed with a mesh of stainless steel.

22. The method according to claim 19 , wherein the balls are contained in a bag and wherein the inert sand forms barrier between the surface of the object and the bag.

23. The method according to claim 22 , wherein the bag is formed with a mesh of stainless steel.

Assignees

• Stratasys Ltd

Inventors

• Hirsch Shai
• Sheinman Yehoshua

Classifications

• B22F3/1003 Primary

  Use of special medium during sintering, e.g. sintering aid · CPC title

• B22F10/64

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

• B33Y40/20 Primary

  Post-treatment, e.g. curing, coating or polishing · CPC title

• B22F2003/1042

  with support for articles to be sintered · CPC title

• B22F2301/052

  Aluminium · CPC title