Patent attributes
A cermet insert having a structure composed of a hard phase and a binding phase and, as a sintered body composition, containing Ti, Nb and/or Ta, and W in a total amount of Ti in terms of carbonitride, Nb and/or Ta in terms of carbide and W in terms of carbide of 70 to 95 wt. % of an entirety of the microstructure, and containing W in terms of carbide in an amount of 15 to 35 wt. % of the entirety of the microstructure, the sintered body composition further containing Co and/or Ni. The hard phase has one or two or more of the phases: (1) a first hard phase of a core-having structure whose core portion contains a titanium carbonitride phase and a peripheral portion containing a (Ti, W, Ta/Nb)CN phase, (2) a second hard phase of a core-having structure whose core portion and peripheral portion both contain a (Ti, W, Ta/Nb)CN phase, and (3) a third hard phase of single-phase structure including a titanium cabonitride phase. Moreover, the titanium carbonitride phase includes a W-rich phase unevenly distributed in the titanium carbonitride phase.
