CEMENTED CARBIDE CUTTING DRILL EXERTING EXCELLENT WEAR RESISTANCE BY HIGH SPEED CUTTING

摘要

PROBLEM TO BE SOLVED: To provide a cemented carbide cutting drill exerting excellent wear resistance by high speed cutting.;SOLUTION: This cemented carbide cutting drill is made of cemented carbide to be a sintered body of green compact having a composition made of Co: 8 to 10%, composite carbide having of W and Ti: 20 to 30% having a composition formula: (W1-YTiY) C (Y shows 0.3 to 0.6 at an atomic ratio), niobium carbide: 5 to 10% and tungsten carbide: remnants, in mass %. In the cemented carbide, a dispersed phase constituted of a tungsten carbide phase, a core part constituted of composite carbide of W and Ti and a surrounding part constituted of composite carbide of W, Ti and Nb form a cored structure composite carbide phase and a combined phase has a structure made of Co-W alloy, by a structural observation by a scanning type electronic microscope.;COPYRIGHT: (C)2002,JPO