cubic boron nitride containing group ultra-high pressure sintered body and a cutting tool that this tool substrate, the surface coating cutting tool

摘要

PROBLEM TO BE SOLVED: To provide a cBN-group ultra-high pressure sintered body with superior toughness, a cutting tool using the same as a tool base and having superior chipping resistance and wear resistance, and a surface coated cutting tool.SOLUTION: There are provided a cBN-group ultra-high pressure sintered body containing cBN particles, a binder phase, and a TiBphase, and a cutting tool using the same as a tool base and a coated cutting tool. The coated cutting tool is characterized in that: an average particle size of the cBN particles is 0.5-3.5 μm and the content is 40-75 vol%; a fine Ti boride phase of 50-500 nm in an average particle size is dispersed and distributed in the binder phase; the production amount Y (vol%) of the TiBphase in the sintered body and the content X (vol%) of the cBN particles satisfy (-0.05X+4.5)≤Y≤(-0.2X+18); and the content rate of the TiBphase which does not come in contact with the cBN particles in the sintered body is 15-65 vol% for the whole TiBphase contained in the sintered body.