PURPOSE: To reduce the cost of machining by calcining a press molding contg. ≥1 kinds of nitrides, such as Si3N4, AlN, TiN, ZrN, at specific ratios in a reducing or neutral gas and machining the molding, then firing the molding in an inert gas.
CONSTITUTION: A proper ratio of binders, such as stearic acid and PVA, are mixed with a nitride material contg. ≥30vol.% in total one or ≥2 kinds among the nitrides, such as Si3N4, AlN, TiN, ZrN, and after the mixture is granulated, the granules are press molded. This molding is degreased and calcined in the atm. or reducing or neutral gas, such as H2, N2 or Ar. The molding is then machined to a desired shape and is further sintered in the inert gas, such as N2, to obtain the nitride sintered body. The degreased and calcined molding is machined by the rotating motion of a grinding wheel of a resinoid type formed by solidifying abrasive grains of Al2O3, Si3N4, etc., with a resin and is sintered in the inert gas, by which the nitride sintered body is obtd.
MUSASA MAMORU
TANABE HIROYUKI
