Method of forming in-situ boron nitride for ceramic matrix composite environmental protection

Patent metadata

Field	Value
Publication number	US-9732005-B2
Application number	US-201514674179-A
Country	US
Kind code	B2
Filing date	Mar 31, 2015
Priority date	Apr 7, 2014
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A method for forming in situ a boron nitride reaction product locally on a reinforcement phase of a ceramic matrix composite material includes the steps of providing a ceramic matrix composite material having a fiber reinforcement material; and forming in situ a layer of boron nitride on the fiber reinforcement material.

First claim

What is claimed is:

1. A method for forming in situ a boron nitride reaction product locally on a reinforcement phase of a ceramic matrix composite material, said method comprising:
providing a ceramic matrix composite material having a fiber reinforcement material;
providing a B4C material and a Si3N4 material and depositing a layer of said B4C material and a layer of said Si3N4 material on said fiber reinforcement material wherein said layer of said B4C material and said layer of said Si3N4 material are deposited sequentially; and
heating said B4C material and said Si3N4 material to a temperature above 1200 degrees Centigrade to form a hexagonal boron nitride reaction product in situ on the fiber reinforcement material by the reaction between B4C and Si3N4.

2. The method of claim 1 , wherein said forming step comprises forming said layer of boron nitride solely on a surface of the fiber reinforcement material.

3. The method of claim 1 , wherein said forming step comprises forming said layer of boron nitride so that said layer of boron nitride solely surrounds the fiber reinforcement material.

4. The method of claim 1 , wherein said providing step comprises providing a silicon based ceramic matrix composite material having a plurality of silicon based reinforcement fibers.

5. The method of claim 4 , wherein said providing step comprises providing said silicon based ceramic matrix composite material with a plurality of fibers selected from the group consisting of silicon carbide (SiC), Si—C—O, Si—N—C—O, Si—B—C—N, carbon, aluminum oxide, zirconium oxide, glass, mullite, and silicon nitride fibers.

6. The method of claim 1 , wherein said heating step comprises heating to a temperature in the range of from 1400 degrees Centigrade to 1500 degrees Centigrade to form said boron nitride reaction product.

Assignees

• United Technologies Corp

Inventors

• Magdefrau Neal
• Sheedy Paul

Classifications

• C04B2235/524

  Non-oxidic, e.g. borides, carbides, silicides or nitrides · CPC title

• C04B2235/656

  characterised by specific heating conditions during heat treatment · CPC title

• C04B35/62894

  with more than one coating layer · CPC title

• C04B35/80 Primary

  Fibres, filaments, whiskers, platelets, or the like · CPC title

• C04B2235/3821

  Boron carbides · CPC title