摘要 |
A superhard tip which has wearing resistance on the edge side and has toughness on the bonding side. The superhard tip is made of a superhard alloy having a composition in which the proportion of WC to Co is substantially even from the edge side to the bonding side. The alloy has a gradient composition in which the content of a binder metal increases from the edge side to the bonding side, the binder metal being one which does not form a eutectic structure with WC or one which has a WC eutectic point higher than the eutectic point for the WC-Co superhard alloy and has a melting point not lower than the liquid-phase sintering temperature of the WC-Co superhard alloy. |