CBN SINTERED BODY FOR HIGH SURFACE INTEGRITY MACHINING, CBN SINTERED BODY CUTTING TOOL, AND CUTTING METHOD USING THE SAME

摘要

To provide a high cBN content ratio sintered body that improves fatigue life of the machined part and has a longer tool lifespan than conventional cBN sintered body tools by suppressing the production of the affected layer by machining formed on the machined surface of the workpiece to be cut and by promoting residual compression stress. That is a cBN sintered body according to the present invention is a cBN sintered body for high surface integrity machining having a cBN component of not less than 87% and not more than 99% by volume% and a thermal conductivity of 100 W/m.cndot.K or more; and the outermost surface of the cBN sintered body 1 is coated with a heat resistant film 2 having a thickness of 0.5 .mu.m to 12 .mu.m comprising a compound of at least one element selected from 4a, 5a, 6a group elements and A1, and at least one element selected from C, N, and O.