HIGH-PRESSURE PHASE BORON NITRIDE BASE SINTER

摘要

A high-pressure phase boron nitride-based high-hardness high-strength sintered body for cutting tools represented by a milling tool and an end mill etc., which is improved in wear resistance and chipping resistance, is obtained. The high-pressure phase boron nitride-based sintered body according to the present invention comprises a plurality of grains (1) of high-pressure phase boron nitride and a binder phase (2, 3), and the content of the aforementioned grains (1) is at least 20.0 volume % and not more than 99.7 volume %. The aforementioned binder phase (2, 3) includes a first binder phase (2) enclosing the aforementioned grains (1) and a second binder phase (3) other than that. The first binder phase (2) consists of the form of at least either a nitride of at least one of Ti, TiA l , Zr and Hf or a solid solution thereof. The aforementioned second binder phase (3) includes a grain growth suppressive binder phase (4) between a plurality of the aforementioned grains (1) enclosed with the aforementioned first binder phase (2). <IMAGE>