High-pressure phase boron nitride sintering body and its production manner null for cutting tool

摘要

PURPOSE:To manufacture a high pressure phase BN sintered body having exceedingly improved cuttability by blending high pressure phase BN constituted of cBN and wBN blended under specified conditions with a bonding phase of intermetallic compounds constituted of the carbide or the like of the 4a in a periodic table with an Al metal or the like in specified ratios. CONSTITUTION:A high pressure phase boron nitride sintered body is manufactured by blending 10 to 80vol.% high pressure phase boron nitride constituted of 95 to 99.9vol.% cubic system boron nitride (cBN) having 5mu grain size and 0.1 to 5vol.% wurtzite type boron nitride (wBN) having =1mu grain size with 20 to 90vol.% intermetallic compounds constituted of at least one kind among the carbides, nitridess and borides of the 4a, 5a and 6a in a periodic table (such as titanium nitride, tantalum carbide and titanium boride) or their mixture or mutual solid soln. with at least one kind of metal among Al, Ni, Si, Co, Cr and W. In this way, a high hardness sintered body suitable for machining hardened steels having high hardness or the like can be obtd.