| 摘要 |
A sintered body contains a high pressure form boron nitride in the range of 20 to 70% by volume, a first binding material surrounding the high pressure form boron nitride with a thickness in the range of 5nm to 300nm and a second binding material of the balance. The first binding material is composed of at least one of nitride and boride of Ti and Al. The second binding material is composed of at least one selected from the group consisting of nitride, carbide, carbonitride, boride and oxide of Al and transition metals belonging to the group 4a, 5a and 6a in the periodic table and mutual solid solution thereof. Supposing that X is the amount of Al contained per unit volume in the first binding material and Y is the amount of Al contained per unit volume in the second binding material, the ratio X/Y is not less than 1. |
