| abstract |
PROBLEM TO BE SOLVED: To provide a cutting tool excellent in wear resistance, particularly crater wear resistance, in cutting hard-to-hard materials and high-speed, high-efficiency cutting of iron-based materials. SOLUTION: At least a part of a surface involved in cutting in a cBN-based sintered body base material is provided with at least one Al 2 O 3 layer. This sintered body base material contains 20 to 99% by volume of cBN and 1.0 to less than 10% by volume of Al 2 O 3 having an average particle size of 1 μm or less. The Al 2 O 3 layer has a thickness of 0.5 μm to 50 μm. When the thickness d of the Al 2 O 3 layer is 0.5 μm ≦ d ≦ 25 μm, the average crystal grain size (s) is 0.01 μm ≦ s ≦ 4 μm and 25 μm < When d ≦ 50 μm, 0.01 μm ≦ s ≦ 10 μm. Abrasion resistance under high temperature and high load by using a cBN base sintered body with excellent plastic deformation resistance at high temperature as a base material and coating Al 2 O 3 with excellent chemical stability with good adhesion. In particular, it has excellent crater resistance. |