Patent ID: 7112235

Claim:
A cutting insert comprising a cubic boron nitride based ultra-high pressure sintered material exhibiting, in a structural observation using an electron microscope, a substantially three-phase structure including a continuously bonded phase, a hard dispersed phase, and an intermediate adhesion phase intervening between the continuously bonded phase and the hard dispersed phase, wherein the cubic boron nitride based ultra-high pressure sintered material consists of: 15 to 56 wt % of at least two components selected from titanium nitride, titanium carbonitride, and titanium carbide, or 15 to 56 wt % of titanium carbonitride, for forming the continuously bonded phase; 2 to 10 wt % of a nitride compound having titanium and aluminum and 2 to 10 wt % of tungsten carbide, for forming the intermediate adhesion phase; and 35 to 65 wt % of the cubic boron nitride, as the balance, for forming the hard dispersed phase.