Densified polymer infiltrated and pyrolysis-based cmc articles

Patent metadata

Field	Value
Publication number	US-2016229757-A1
Application number	US-201415022615-A
Country	US
Kind code	A1
Filing date	Sep 12, 2014
Priority date	Sep 19, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

A method of densifying a CMC article includes the steps of pyrolyzing a CMC article until a desired initial porosity is achieved, coating CMC pores within the CMC article with carbon, pyrolyzing the carbon to form carbon pores, coating the carbon pores with silicon, and heat treating the CMC article to create a silicon carbide filled pore integrated with silicon carbide of the CMC article to densify the CMC article.

First claim

What is claimed is:

1 . A method of densifying a CMC article comprising the steps of:
pyrolyzing a CMC article until a desired initial porosity is achieved; coating CMC pores within the CMC article with carbon; pyrolyzing the carbon to form carbon pores; coating the carbon pores with silicon; and heat treat the CMC article to create a silicon carbide filled pore integrated with silicon carbide of the CMC article to densify the CMC article.

2 . The method according to claim 1 , wherein the CMC article is pyrolyzed more than once to achieve the initial porosity.

3 . The method according to claim 2 , wherein the CMC article is pyrolyzed less than six times to achieve the initial porosity.

4 . The method according to claim 1 , wherein the CMC article is pyrolyzed at a temperature of 1000-1400° C. to achieve the initial porosity.

5 . The method according to claim 1 , wherein the CMC pore coating step includes infiltrating the CMC pores with a carbon precursor resin.

6 . The method according to claim 5 , wherein the carbon precursor resin includes fillers selected from the group including silicon, silicon carbide, boron carbide and silicon nitride.

7 . The method according to claim 1 , wherein the carbon is pyrolyzed at a temperature of 1000-1800° C.

8 . The method according to claim 7 , wherein the silicon enters the carbon pores by capillary action.

9 . The method according to claim 1 , wherein the densified article is machined to a desired shape.

10 . The method according to claim 9 , wherein a seal coat is applied to the machine shape.

11 . The method according to claim 10 , wherein an environmental barrier coating is applied to the seal coating.

12 . The method according to claim 1 , wherein the CMC article is densified by infiltrating the article with a silicon carbide precursor resin.

13 . The method according to claim 12 , wherein the CMC article is pyrolyzed at 1200-1800° C.

14 . The method according to claim 12 , wherein the silicon carbide precursor resin includes a filler selected from the group including silicon, silicon carbide, boron carbide and silicon nitride.

15 . The method according to claim 1 , wherein CMC fibers are arranged about a form and a silicon carbide precursor resin is injected into a mold to provide the CMC article.

16 . The method according to claim 15 , wherein the CMC fibers are wrapped about the form.

17 . The method according to claim 15 , wherein the silicon carbide precursor resin includes a filler selected from the group including silicon, silicon carbide, boron carbide and silicon nitride.

18 . The method according to claim 15 , wherein the CMC fibers are provided as a prepreg.

19 . The method according to claim 15 , wherein the CMC article in the mold is heated to a temperature of 100-600° C. and is removed from the mold.

20 . The method according to claim 15 , wherein the CMC article is placed in a fixture and pyrolyzed to a temperature of 1000-1400° C.

Assignees

• United Technologies Corp

Inventors

• Mccaffrey Michael G
• Berczik Douglas M

Classifications

• C04B2235/3826

  Silicon carbides · CPC title

• B05D3/007

  After-treatment · CPC title

• C04B2235/5248

  Carbon, e.g. graphite · CPC title

• C04B2235/616

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

• C04B2235/3821

  Boron carbides · CPC title