Multilayer interface coating with thermally-grown oxide for improved durability
AssigneeRtx Corporation
InventorEvan B. Callaway
Life of this patent
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Abstract
A coated fiber structure for use in a ceramic matrix composite comprises a fiber and a coating system applied to and circumscribing the fiber. The coating system comprises a first boron nitride layer, a silicon carbide layer extending coaxially with and in direct contact with the first boron nitride layer, a first thermally-grown oxide layer formed on the silicon carbide layer, and a second boron nitride layer extending coaxially with and in direct contact with the first thermally-grown oxide layer.
Claims16
A coated fiber structure for use in a ceramic matrix composite, the coated fiber structure comprising:
- a fiber comprising silicon carbide;
- and
- a coating system applied to and circumscribing the fiber, the coating system comprising:
- a first thermally-grown oxide layer formed on the fiber, wherein the first thermally-grown oxide layer comprises silica;
- a first boron nitride layer extending coaxially with and in direct contact with the first thermally-grown oxide layer, wherein the first boron nitride layer comprises an anisotropic region adjacent to the first thermally grown oxide layer;
- a silicon carbide layer extending coaxially with and in direct contact with the first boron nitride layer;
- a second thermally-grown oxide layer formed on the silicon carbide layer, wherein the second thermally-grown oxide layer comprises silica;
- and
- a second boron nitride layer extending coaxially with and in direct contact with the second thermally-grown oxide layer, wherein the second boron nitride layer comprises an anisotropic region adjacent to the second thermally grown oxide layer.
A method of forming a ceramic matrix composite, the method comprising:
- forming a fibrous preform by:
- arranging a plurality of ceramic fibers;
- forming a first thermally-grown oxide layer on the plurality of ceramic fibers;
- depositing a first boron nitride layer on the first thermally-grown oxide layer, wherein the first boron nitride layer extends coaxially and is in direct contact with the first thermally-grown oxide layer;
- depositing a silicon carbide layer on the first boron nitride layer;
- forming a second thermally-grown oxide layer on the silicon carbide layer, wherein the second thermally-grown oxide layer comprises silica;
- and
- depositing a second boron nitride layer on the second thermally-grown oxide layer, wherein the second boron nitride layer extends coaxially and is in direct contact with the second thermally-grown oxide layer;
- and
- depositing a silicon carbide matrix on the fibrous preform.
Dependencies are inferred from the claim text.