| abstract |
It is a composite sintered body composed of cubic boron nitride particles and hexagonal nitride boron particles, or hexagonal nitride boron nitride particles and wurtzite type boron nitride particles, and the dislocation density of the cubic boron nitride particles is 1 × 10 15 / m 2 or more and 1 × 10 17 / m 2 or less, and the median diameter d50 of the equivalent circle diameter of the cubic boron nitride particles is 10 nm or more and 500 nm or less, and the volume of the cubic boron nitride particles is The reference content Vc, the volume-based content Vh of the hexagonal boron nitride particles, and the volume-based content Vw of the wurtzite-type boron nitride particles satisfy the relationship of the following formula 1. Equation 1: 0.015 ≦ (Vh + Vw) / (Vc + Vh + Vw) ≦ 0.5 It is a composite sintered body. |