초록 ▼

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 1,500째 C. The coating may have p

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 1,500째 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.

대표청구항 ▼

We claim as our invention: 1. 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

We claim as our invention: 1. 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. 2. The article of claim 1, wherein the xenotime phosphate compound comprises yttrium phosphate. 3. The article of claim 1, further comprising: the non-oxide ceramic substrate comprises one of the group of silicon carbide and silicon nitride; and the oxygen barrier layer comprises one of the group of mullite, zircon, zirconium phosphate, and yttrium silicate. 4. The article of claim 1, further comprising the overlayer of xenotime phosphate compound having a porosity of at least 10%. 5. The article of claim 1, further comprising the overlayer of xenotime phosphate compound having a porosity of at least 15%. 6. The article of claim 1, wherein the non-oxide ceramic substrate comprises silicon. 7. The article of claim 1, further comprising the overlayer of xenotime phosphate compound having a thickness of greater than 0.1 mm. 8. 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. 9. The article of claim 8, wherein the xenotime phosphate compound comprises yttrium phosphate. 10. The article of claim 8, wherein the xenotime phosphate compound comprises yttrium phosphate and the layer of ceramic oxide insulating material comprises mullite. 11. The article of claim 10, further comprising the layer of yttrium phosphate compound having a thickness of greater than 0.1 mm. 12. The article of claim 8, further comprising the xenotime phosphate compound comprising a porosity of at least 10%. 13. The article of claim 8, further comprising the xenotime phosphate compound comprising a porosity of at least 15%. 14. The article of claim 8, wherein the ceramic oxide insulating material comprises silicon.