SILICON NITRIDE-BASED CERAMIC MEMBER

摘要

Provided is a silicon nitride-based ceramic member which is not visible under visible light but is discernible under ultraviolet light. The silicon nitride-based ceramic member is a molded body having a polished surface and comprising a base material sintered body on which surface a fluorescent material sintered body is disposed. The base material sintered body is a ceramic that includes a compound of at least one element selected from transition metal elements and alkaline earth metal elements, the balance being silicon nitride of at least 65 mass% or more. The fluorescent material sintered body is a ceramic that include a compound of at least one element selected from transition metal elements and alkaline earth metal elements and a lanthanide element compound, the balance being silicon nitride of at least 65 mass% or more. Under ultraviolet light illumination, the surface phase of the base material sintered body and the surface phase of the fluorescent material sintered body appear on the polished surface in such a manner that the shapes thereof can be identified.