摘要 |
The invention provides a cutting tool made from a cubic boron nitride sintering material which demonstrates excellent resistance to defects in intermittent cutting machining of high-hardness steel. According to the cutting tool made from the cubic boron nitride sintering material, optimally an average particle size of a cubic boron nitride particle is 0.5 to 8 [mu]m; at least pat of the surface of the cubic boron nitride particle is coated by an oxygen-containing aluminum nitride film with the average thickness of 10 to 100 [mu]m and an everage oxygen concentration being 1 to 15 atom%; furthermore, the oxygen-containing aluminum nitride film covering the surface of the cubic boron nitride particle has a local crack; and the average formation proportion of the local crack h/H satisfies 002<=h/H<=0.08, with h representing the length of the crack of the oxygen-containing aluminum nitride film and H representing the perimeter of the cubic boron nitride particle. |