| abstract |
A high-pressure phase boron nitride-based high-hardnessnhigh-strength sintered body for cutting toolsnrepresented by a milling tool and an end mill etc., whichnis improved in wear resistance and chipping resistance, isnobtained. n The high-pressure phase boron nitride-based sinterednbody according to the present invention comprises anplurality of grains (1) of high-pressure phase boronnnitride and a binder phase (2, 3), and the content of thenaforementioned grains (1) is at least 20.0 volume % andnnot more than 99.7 volume %. The aforementioned bindernphase (2, 3) includes a first binder phase (2) enclosingnthe aforementioned grains (1) and a second binder phasen(3) other than that. The first binder phase (2) consistsnof the form of at least either a nitride of at least onenof Ti, TiAℓ, Zr and Hf or a solid solution thereof. Thenaforementioned second binder phase (3) includes a grainngrowth suppressive binder phase (4) between a plurality ofnthe aforementioned grains (1) enclosed with thenaforementioned first binder phase (2). |