Method for closed pore ceramic

Patent metadata

Field	Value
Publication number	US-2021107839-A1
Application number	US-202016889068-A
Country	US
Kind code	A1
Filing date	Jun 1, 2020
Priority date	May 30, 2007
Publication date	Apr 15, 2021
Grant date	—

Abstract

A method includes forming a ceramic member that has a plurality of closed pores within a ceramic matrix. The forming includes compacting a ceramic powder to form intra-particle pores between particles of the ceramic powder, and sintering the compacted ceramic powder to cause diffusion of the ceramic powder and formation of the ceramic matrix. The diffusion does not fill the intra-particle pores and leaves the closed pores.

First claim

What is claimed is:

1 . A method comprising:
forming a ceramic member that has a plurality of closed pores within a ceramic matrix, wherein the forming includes
compacting a ceramic powder to form intra-particle pores between particles of the ceramic powder, and
consolidating the compacted ceramic powder to cause diffusion of the ceramic powder and formation of the ceramic matrix, wherein the diffusion does not fill the intra-particle pores and leaves the closed pores.

2 . The method as recited in claim 1 , wherein the compacting compacts the ceramic powder to 40% to 60% theoretical density.

3 . The method as recited in claim 2 , wherein the compacting compacts the ceramic powder to about 50% theoretical density.

4 . The method as recited in claim 2 , wherein the ceramic matrix includes at least one of yttria stabilized zirconia, zirconia, hafnia, gadolinia, molybdenum disulphide, alumina, or mullite.

5 . The method as recited in claim 1 , wherein the ceramic member has 20 vol % to 80 vol % of the closed pores.

6 . The method as recited in claim 1 , wherein the ceramic member has 33 vol % to 66 vol % of the closed pores.

7 . The method as recited in claim 6 , wherein the ceramic matrix includes at least one of zirconia, hafnia, or gadolinia.

8 . The method as recited in claim 7 , wherein the sintering is partial sintering such that the ceramic powder is less than 100% sintered in the final ceramic member.

9 . The method as recited in claim 7 , wherein the sintering is partial sintering prior to the ceramic powder forming equiaxed ceramic crystals.

10 . A method comprising:
forming a ceramic member that has a plurality of closed pores within a ceramic matrix, wherein the closed pores are not fluidly interconnected with each other or with a surrounding environment of the ceramic member, and the forming includes compacting a ceramic powder to 40% to 60% theoretical density, and sintering the compacted ceramic powder to cause diffusion of the ceramic powder and formation of the ceramic matrix with the closed pores.

11 . The method as recited in claim 10 , wherein the compacting compacts the ceramic powder to about 50% theoretical density.

12 . The method as recited in claim 10 , wherein the ceramic matrix includes at least one of yttria stabilized zirconia, zirconia, hafnia, gadolinia, molybdenum disulphide, alumina, or mullite.

13 . The method as recited in claim 12 , wherein the ceramic member has 33 vol % to 66 vol % of the closed pores.

14 . The method as recited in claim 13 , wherein the sintering is partial sintering prior to the ceramic powder forming equiaxed ceramic crystals.

15 . A method comprising:
forming a ceramic member that has a plurality of closed pores within a ceramic matrix, wherein the closed pores are not fluidly interconnected with each other or with a surrounding environment of the ceramic member, and the forming includes compacting a ceramic powder to 40% to 60% theoretical density with intra-particle pores between particles of the ceramic powder, and partially sintering the compacted ceramic powder to cause diffusion of the ceramic powder and formation of the ceramic matrix, wherein the diffusion does not fill the intra-particle pores and leaves the closed pores.

16 . The method as recited in claim 15 , wherein the compacting compacts the ceramic powder to about 50% theoretical density.

17 . The method as recited in claim 15 , wherein the ceramic matrix includes at least one of zirconia, hafnia, or gadolinia.

18 . The method as recited in claim 17 , wherein the ceramic member has 33 vol % to 66 vol % of the closed pores.

19 . The method as recited in claim 17 , wherein the partial sintering is prior to the ceramic powder forming equiaxed ceramic crystals.

Assignees

• Raytheon Tech Corp

Inventors

• Tholen Susan M
• Strock Christopher W

Classifications

• C04B35/64

  Burning or sintering processes (C04B33/32 takes precedence {; powder metallurgy B22F}) · CPC title

• C04B2235/608

  Green bodies or pre-forms with well-defined density · CPC title

• C04B38/0061 Primary

  closed porosity · CPC title

• B28B3/00

  Producing shaped articles from the material by using presses (shaping on moving conveyors B28B5/00); Presses specially adapted therefor (presses in general B30B) · CPC title

• F01D25/005

  Selecting particular materials · CPC title