Apparatus for producing a silicon nitride sintered body

Abstract

Provided is an apparatus for producing a silicon nitride sintering body made of a furnace including a heater source. The furnace includes a furnace core chamber defined by at least one partition inside the furnace to prevent an atmosphere containing more than about 30 ppm of carbon monoxide from contacting said silicon nitride sintered body. At least an inner surface of the partition is made of a carbon-free heat-proof material which prevents formation of carbon monoxide gas in an atmosphere in contact with the silicon nitride sintered body during sintering. The furnace also includes a gas supply pipe for supplying an N.sub.2 gas or an inactive gas including an N.sub.2 gas into the furnace core. Also provided is a sintering case made of a vessel defining a sintering atmosphere. The vessel has an opening for loading an object to be sintered into the vessel. At least an inner surface of the vessel is made of a carbon-free heat proof material which prevents the formation of carbon monoxide gas in the sintering atmosphere. The vessel also includes a lid for covering the opening. At least an inner surface of the lid is made of a carbon-free heat proof material which prevents the formation of carbon monoxide gas in the sintering atmosphere.