Protective overlayer for ceramics
AssigneeSiemens Westinghouse Power Corporation
InventorsChristian X. Campbell, Jay E. Lane
Life of this patent
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Abstract
A xenotime phosphate protective overlayer (22) for protecting a ceramic material (24) from a high temperature, moisture-containing environment. Yttrium phosphate may be used as a protective overlayer to protect an underlying mullite layer to temperatures in excess of 1,500° C. The coating may have porosity of greater than 15% for improved thermal shock protection. To prevent the ingress of oxygen to an underlying ceramic non-oxide material, such as silicon carbide or silicon nitride, an oxygen barrier layer (34) is disposed between the xenotime phosphate coating and the non-oxide material. Such a protective overlayer may be used for an article having a ceramic matrix composite substrate.
Claims14
An article adapted for use in a combustion environment, the article comprising:
- a non-oxide ceramic substrate;
- an oxygen barrier layer disposed on the non-oxide ceramic substrate;
- and
- an overlayer of xenotime phosphate compound disposed on the oxygen barrier layer and defining a surface exposed to the combustion environment.
An article adapted for use in a combustion environment, the article comprising:
- a ceramic matrix composite substrate;
- a layer of ceramic oxide insulating material comprising mullite disposed on the substrate;
- and
- a layer of a xenotime phosphate compound disposed on the layer of insulating material and defining a surface exposed to the combustion environment.
Dependencies are inferred from the claim text.