【発明の名称】高精度加工工具用焼結体

Japanese Patent JPH0694580

B2

A sintered body for high-accuracy working tools is obtained by sintering mixed powder containing at least 45 percent by volume and not more than 60 percent by volume of cubic boron nitride powder of not more than 2 mu m in average particle size and having a remainder formed of binder powder under a superhigh pressure. The binder contains at least 5 percent by weight and not more than 15 percent by weight of Al and at least 2 percent by weight and not more than 20 percent by weight of W, and has a remainder formed of Ti compound(s). The atomic ratio of Ti contained in the binder to transition metal element(s) belonging to the group IVa, Va and/or VIa of the periodic table including Ti is at least 2/3 and not more than 97/100. In the structure of the sintered body, cubic boron nitride crystals are bonded with each other through bonding phases formed by the binder. When at least one or more Ti compounds are selected from a group of TiNz, Ti(C1-xNx)z, (Ti,M)(C1-xNx)z and (Ti,M)Nz, where M represents transition metal element(s) belonging to the group IVa, Va and/or VIa of the periodic table excluding Ti, 0.45