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US 6,645,649 B2Granted
Surface-coated sintered body of silicon nitride
AssigneeKYOCERA Corporation
InventorsKoichi Tanaka, Takero Fukudome
Life of this patent
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Abstract
A surface-coated sintered body of silicon nitride wherein a coating layer on the surface comprises a crystalline phase of RE2Si2O7 and/or RE2SiO5 (RE=rare earth element), the crystalline phase having an average crystalline particle diameter of not smaller than 0.1 μm, and the excess amount of SiO2 contained in the coating layer being not larger than 10 mole %. The coating layer formed on the surfaces of the sintered body exhibits excellent adhering force even in a high-temperature zone of around 1500° C. and features a long life.
Claims10
A surface-coated sintered body of silicon nitride comprising:
- a sintered substrate of silicon nitride;
- and
- a coating layer formed on the surfaces of said sintered substrate,
- wherein said coating layer comprises a crystalline phase of RE2Si2O7 and/or RE2SiO5, where RE is a rare earth element,
- wherein said crystalline phase has an average crystalline grain diameter of not smaller than 0.1 μm, and the excess amount of SiO2 contained in the coating layer is not larger than 10 mole %, and
- wherein a molar ratio of SiO2/RE2O3 in the coating layer is from 0.9 to 2.3.
3 more elements
Dependencies are inferred from the claim text.