Ceramic matrix composite structures with controlled microstructures fabricated using chemical vapor infiltration (cvi)

Patent metadata

Field	Value
Publication number	US-2017015595-A1
Application number	US-201514633422-A
Country	US
Kind code	A1
Filing date	Feb 27, 2015
Priority date	Feb 27, 2015
Publication date	Jan 19, 2017
Grant date	—

Abstract

According to a method set forth herein a plurality of preform plies having first and second preform plies can be associated together to define a preform. The preform can be subject to chemical vapor infiltration (CVI) processing to define a ceramic matrix composite (CMC) structure.

First claim

1 . A method comprising:
associating a plurality of preform plies to define a preform, wherein a first preform ply and a second preform ply of the plurality of preform plies have different average pore sizes; and subjecting the preform to chemical vapor infiltration (CVI) to define a densified ceramic matrix composite (CMC) structure.

2 . The method of claim 1 , wherein the first preform ply has a first average pore size, wherein the second preform ply has a second average pore size and wherein second average pore size is greater than the first average pore size.

3 . The method of claim 1 , wherein the first preform ply is a center preform ply having first average pore size, wherein the second preform ply is an outer surface preform ply defining an outer surface of the preform, and wherein the second preform ply has a second average pore size greater than the first average pore size.

4 . The method of claim 1 , wherein the plurality of preform plies includes a third preform ply, wherein the second preform ply is disposed at a first side of the first preform ply, wherein the third preform ply is disposed at a second side of the first preform ply, and wherein the second preform ply and the third preform ply each have larger average pore size than an average pore size of the first preform ply.

5 . The method of claim 1 , wherein a count of the plurality of preform plies is selected from the group consisting of (a) more than 1 preform plies, (b) more than 5 preform plies, (c) more than 20 preform plies, (d) more than 50 preform plies, and (e) more than 100 preform plies.

6 . The method of claim 1 , wherein a preform defined by the plurality of preform plies is a solid structure, wherein the plurality of preform plies includes a center preform ply, a first set of preform plies from the center perform ply to a preform ply defining a first outer surface of the preform having increasing average pore sizes, and a second set of preform plies from the center perform ply to a preform ply defining a second outer surface of the preform having increasing average pore sizes.

7 . The method of claim 1 , wherein the preform is a hollow structure preform, wherein the plurality of preform plies of the preform define a sidewall of the hollow structure preform, wherein the plurality of preform plies includes a center preform ply, a first set of preform plies from the center perform ply to a preform ply defining an outer surface of the hollow structure preform having increasing average pore sizes, and a second set of preform plies from the center perform ply to a preform ply defining an inner surface of the hollow structure preform having decreasing average pore sizes.

8 . The method of claim 1 , wherein the preform is a hollow structure preform, wherein the plurality of preform plies of the preform define a sidewall of the hollow structure preform, wherein a certain preform ply of the plurality of preform plies that defines an inner surface of the hollow structure preform has a smallest average pore size of the plurality of preform plies, and wherein preform plies of the plurality of preform plies in a succession of locations from a location of the certain preform ply to a location of a preform ply that defines an outer surface of the hollow structure preform have increasing average pore sizes.

9 . The method of claim 1 , wherein the method includes performing a process for fabricating one or more preform ply of the plurality of preform plies.

10 . The method of claim 9 , wherein the performing a process for fabricating includes using a pore former.

11 . The method of claim 9 , wherein the performing a process for fabricating includes using a filler.

12 . The method of claim 1 , wherein the method includes controlling an average pore size of one or more preform ply of the plurality of preform plies, and wherein the controlling an average pore size of the one or more preform ply includes adding or reducing an amount of filler used during a pyrolysis process for fabrication of one or more preform ply of the plurality of preform plies.

13 . The method of claim 1 , wherein the method includes controlling an average pore size of one or more preform ply of the plurality of preform plies, and wherein the controlling an average pore size of the one or more preform ply includes controlling a characteristic of a pore former used during fabrication of one or more preform ply and the plurality of preform plies.

14 . The method of claim 1 , wherein the method includes shaping the preform into a shape of a turbine component.

15 . The method of claim 1 , wherein the method includes shaping the preform into a shape of a turbine component, and providing one or more center preform plies of the plurality of preform plies to have smaller average pore sizes than one or more outer surface preform ply of the plurality of preform plies.

16 . A structure comprising:
a plurality of preform plies associated together to define a preform; wherein a first preform ply and a second preform ply of the plurality of preform plies have different average pore sizes.

17 . The structure of claim 16 , wherein the second preform ply has a larger average pore size than the first preform ply.

18 . The structure of claim 16 , wherein the first preform ply is a center ply having a first average pore size wherein the second preform ply has a second average pore size, the second average pore size being larger than the first average pore size.

19 . The structure of claim 16 , wherein the plurality of preform plies includes a third preform ply, wherein the second preform ply is disposed at a first side of the first preform ply, wherein the third preform ply is disposed at a second side of the first preform ply, and wherein the second preform ply and the third preform ply each have a larger average pore size than an average pore size of the first preform ply.

20 . The structure of claim 16 , wherein a center preform ply of the plurality of preform plies has a smallest average pore size of the plurality of preform plies, and wherein preform plies at successive locations from a location of the center preform ply to a location of a preform ply defining an outer surface of the preform have increasing average pore sizes.

21 . The structure of claim 16 , wherein the preform has a plurality of plies, each successive ply having larger average pore size than the innermost ply

22 . The structure of claim 16 , wherein the preform is in a shape of a turbine component.

23 . The structure of claim 16 , wherein the preform is in a shape of a turbine component, and wherein one or more center ply of the plurality plies has a smaller average pore size than one or more end ply of the plurality of plies that defines an outer surface of the preform.

24 . The structure of claim 16 , wherein the first preform ply includes fibers.

25 . The structure of claim 24 , wherein the fibers include unidirectional fibers.

26 . The structure of claim 24 , wherein the fibers include woven fibers.

27 . The structure of claim 24 , wherein the fibers include a combination of unidirectional fibers and woven fibers.

28 . The structure of claim 24 , wherein a coating is formed on the fibers.

29 . The structure of claim 16 , wherein a count of the plurality of preform plies is selected from the group consisting of (a) mo

Assignees

• Gen Electric

Inventors

• Weaver Jared Hogg
• Corman Gregory Scot
• Luthra Krishan Lal

Classifications

• C04B2235/5208

  Fibers · CPC title

• C04B37/001 Primary

  directly with other burned ceramic articles · CPC title

• C23C16/045

  Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates · CPC title

• C04B2235/614

  Gas infiltration of green bodies or pre-forms · CPC title

• C04B35/71 Primary

  Ceramic products containing macroscopic reinforcing agents (C04B35/66 takes precedence {; infiltration of a porous ceramic matrix with a material forming a non-ceramic phase C04B41/00, reaction infiltration with Si in order to form SiC C04B35/573, in order to form Si3N4 C04B35/591}) · CPC title