Ceramic matrix composites made by chemical vapor infiltration and methods of manufacture thereof

Patent metadata

Field	Value
Publication number	US-2016229755-A1
Application number	US-201415022995-A
Country	US
Kind code	A1
Filing date	Aug 28, 2014
Priority date	Sep 20, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

The present disclosure relates to ceramic matrix composites made by chemical vapor infiltration, methods of making the ceramic matrix composites, and ceramic matrix composite turbine components for use in a hot gas pathway. A method of fabricating a ceramic matrix composite is provided that can include the steps of: (i) forming a plurality of holes in a ceramic matrix composite preform of desired shape; and (ii) densifying the preform by a chemical vapor infiltration process to form a part or most of the matrix. A ceramic matrix composite is also provided that can be used in hot combustion gases made according to the aforementioned ceramic matrix composite fabrication method described herein.

First claim

What is claimed is:

1 . A method of fabricating a ceramic matrix composite, said method comprising:
forming a plurality of holes in a ceramic matrix composite preform of desired shape, wherein the ceramic matrix composite preform has a first face and an opposing second face that define a thickness of the preform; and densifying the preform by a chemical vapor infiltration process to form a part or most of the matrix.

2 . The method according to claim 1 , wherein local volume fraction of the holes varies from about 0.1% to about 30% over a surface region of the preform, or more particularly from about 2% to about 10% over a surface region of the preform.

3 . The method according to claim 1 , wherein the preform has a porosity of between about 20% to about 80%, or more particularly of between about 40% to about 70%.

4 . The method according to claim 1 , wherein the preform comprises plies with unidirectional fibers; or plies with a 2-D woven architecture, with or without thru-thickness stitching; or a 3-D fiber architecture made by weaving and/or braiding.

5 . The method according to claim 1 , wherein the holes have a cross-dimensional diameter ranging from about 25 microns to about 250 microns, or more particularly from about 50 microns to about 200 microns.

6 . The method according to claim 1 , wherein the volume fraction of the holes is between about 0.5% to about 15% for the entire preform, or more particularly between about 3% to about 10% for the entire preform.

7 . The method according to claim 1 , wherein the holes penetrate the full thickness.

8 . The method according to claim 1 , wherein the holes have a cross-sectional shape selected from the group consisting of a circle, square, rectangle, oval, and any other two-dimensional closed pattern.

9 . The method according to claim 1 , wherein the holes vary in cross-sectional dimension through the preform.

10 . The method according to claim 9 , wherein the holes are tapered.

11 . The method according to claim 9 , wherein the holes are formed by mechanical drilling, laser drilling, electrical discharge machining (EDM), water jet machining, ultrasonic abrasive machining, and/or through the use of a fugitive fiber or rod.

12 . The method according to claim 9 , wherein the matrix is a silicon-containing material.

13 . The method according to claim 12 , wherein the silicon-containing material is selected from the group consisting of silicon carbide, silicon nitride, molybdenum silicide, and mixtures thereof.

14 . The method according to claim 12 , wherein the ceramic matrix composite is a silicon carbide-silicon carbide composite or a continuous fiber reinforced composite.

15 . A ceramic matrix composite formed according to the method of claim 12 .

Assignees

• Gen Electric

Inventors

• Luthra Krishan Lal
• Corman Gregory Scot
• Ramamurthi Badri Narayan

Classifications

• C04B2235/5248

  Carbon, e.g. graphite · CPC title

• C04B2235/3813

  Refractory metal borides · CPC title

• C04B35/584

  based on silicon nitride · CPC title

• C04B2235/3817

  Carbides · CPC title

• C04B2235/3804

  Borides · CPC title