SILICON NITRIDE-BORON NITRIDE COMPOSITE SINTERED COMPACT AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a silicon nitride-baron nitride composite sintered compact having improved frictional characteristics without deteriorating mechanical strength. SOLUTION: The silicon nitride-boron nitride composite sintered compact 2 consists of a continuous phase 3 of silicon nitride(Si3 N4 ) and a dispersed phase 4 of boron nitride(h-BN). The particle size of the dispersed phase 4 is 0.1-3 μm and the boron-nitride (h-BN) content is 10-30 vol.%. The sintered compact 2 is obtd. by reducing and nitriding baron oxide with nitrogen in a nitrogen atmosphere and sintering a porous compact (calcined compact) 2a of silicon nitride while depositing boron nitride in the pores 6 in the porous compact 2a.