| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a surface-coated silicon nitride sintered compact having a coating layer excellent in corrosion resistance in a high temperature combustion gas atmosphere, having high adhesive strength and excellent in erosion resistance. <P>SOLUTION: The surface-coated silicon nitride sintered compact is composed of a substrate of a silicon nitride sintered compact and a coating layer formed on the surface of the substrate. The coating layer comprises a crystalline phase of RE<SB>2</SB>Si<SB>2</SB>O<SB>7</SB>and/or RE<SB>2</SB>SiO<SB>5</SB>(wherein RE is a rare earth element), and the difference of the coefficient of thermal expansion between the substrate and the coating layer is 30% or less. Particularly, the coating layer includes an oxide crystalline phase having a lower coefficient of thermal expansion than that of the crystalline phase of RE<SB>2</SB>Si<SB>2</SB>O<SB>7</SB>and/or RE<SB>2</SB>SiO<SB>5</SB>(wherein RE is a rare earth element). Preferably, RE is at least one selected from Dy, Ho, Er, Tm, Yb, and Lu. <P>COPYRIGHT: (C)2004,JPO |
