PURPOSE: To provide a low-cost sintered compact contg. boron nitride having a high density phase and attaining improved wear resistance, chipping resistance, toughness and shock resistance by sintering by hot pressing or hot isostatic pressure treatment without using an ultrahigh pressure device.
CONSTITUTION: This sintered compact contg. boron nitride having a high density phase is a sintered compact contg. ≥10vol.% coated hard phase obtd. by coating the surfaces of the grains of a hard phase of cubic boron nitride and/or wurtzite type boron nitride with single- or multilayer coating films of at least one among the nitrides and borides of Ti, Zr, Hf, Mo, Al and Si and mutual solid solns. of them. The average thickness of the coating films is ≥2.1μm This sintered compact can be formed by sintering by hot pressing or hot isostatic pressure treatment and a low cost can be attained.
KOBAYASHI MASAKI
KATSUMURA YUJI