Patent ID: 6849207
Filing Date: 2005-02-01
Classification: C04B

Abstract:
1. A silicon nitride sintered material comprising: a silicon nitride component and silicon carbide; wherein said silicon nitride component comprises silicon nitride; said silicon carbide is present in an amount such that a mass ratio of silicon carbide to the silicon nitride component is at least 1:100 and less than 4:100; said silicon carbide has an average particle size of 1 μm or less and is dispersed in the silicon nitride component; and said sintered material has a thermal expansion coefficient of at least 3.7 ppm/° C. between room temperature and 1,000° C. where the silicon nitride component contains a rare earth element in an amount of 15-25 mass % as reduced to a certain oxide thereof,and Cr in an amount of 5-10 mass % as reduced to a certain oxide thereof.