CBN TOOL

PROBLEM TO BE SOLVED: To provide a cBN tool exerting excellent performance in severe cutting. SOLUTION: In this tool, a composite sintered body in which cBN sintered bodies are simultaneously joined to a cemented carbide substrate at ultrahigh pressure and high temperature sintering time or a cBN sintered body is brazed on cemented carbide base metal. In the tool, WC contained in the cemented carbide base metal is made by a particle size distribution of the rates of: fine particle WC having a particle diameter of 0.1 to 2.0μm and 30 to 70 volume% in relation to the whole of WC; and rough particle WC having a particle diameter of over 2.0μm to 12μm and 30 to 70 volume% in relation to the whole of WC. Cr amount contained in the cemented carbide base metal is 0.2 to 1.5 wt.%. COPYRIGHT: (C)2007,JPO&INPIT