| 摘要 |
<p>A hard sintered body for tools is obtained by sintering mixed powder containing at least 20 percent by volume and not more than 70 percent by volume of cubic boron nitride powder and having a remainder formed of binder powder under a superhigh pressure. The binder contains at least 2 percent by weight and not more than 20 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(C,N)z, TiCz, (Ti,M)Nz, (Ti,M)(C,N)z and (Ti,M)Cz, where M represents transition metal element(s) belonging to the group IVa, Va and/or VIa of the periodic table excluding Ti and 0.1 </= z </= 0.45, a sintered body which is excellent in crater wear resistance and applicable to high-speed cutting of steel or cast iron is obtained.</p> |
