SURFACE-COATED BORON NITRIDE SINTERED COMPACT TOOL.

摘要

　In a surface-coated boron nitride sintered compact tool according to the present invention, at least a cutting blade portion includes a compound sintered compact and a coating layer provided on a surface of the compound sintered compact. The compound sintered compact includes cubic boron nitride particles and binder particles. The compound sintered compact includes the cubic boron nitride particles in a ratio of 45 vol% to 80 vol%. A first particle size distribution curve of the cubic boron nitride particles has one or more peaks in the particle diameter range of 0.1 µm to 0.7 µm. A second particle size distribution curve of the cubic boron nitride particles has a first peak having a maximum peak height in the particle diameter range of 2.0 µm to 7.0 µm. In the second particle size distribution curve, the integral value ratio (Io/It × 100) is 1 to 20, where Io represents the integral value in the particle diameter range of 0.1 µm to 0.7 µm, and It represents the integral value for the entire range.