Silicon nitride sintered body

摘要

A silicon nitride sintered body comprising (alpha)-silicon nitride including (alpha)'-sialon and (beta)'-sialon including (beta)-silicon nitride in which the content of the (alpha)-silicon nitride including (alpha)'-sialon in the surface part thereof is less than its content in the inner part thereof. The silicon nitride sintered body is excellent in mechanical strength at ordinary temperature, productivity and cost efficiency.