SURFACE-COVERED CEMENTED CARBIDE CUTTING TOOL HAVING HARD COVERING LAYER FOR EXHIBITING SUPERIOR ABRASION RESISTANCE IN HIGH SPEED CUTTING WORK

摘要

PROBLEM TO BE SOLVED: To provide a surface-covered cemented carbide cutting tool having a hard covering layer for exhibiting superior abrasion resistance in high speed cutting work. SOLUTION: The hard covering layer is physically deposited in the whole average layer thickness of 1 to 15μm composed of composite nitride of Al, Ti and Mg on a surface of a WC group cemented carbide base body or a titanium carbonitride cermet base body, and is composed of a hard covering layer having a component concentration distribution structure for allowing a Ti minimum containing point (hereinafter referred to as a point A) and a Ti maximum containing point (hereinafter referred to as a point B) to alternately repeatedly exist at a prescribed interval in the layer thickness direction with the Ti content to continuously varying to the point A from the point B and to the point B from the point A, and having the point B having a composition formula : (Al1-(x+z)TixMgz)N (here, X is 0.35 to 0.55; Z is 0.01 to 0.15 in the atomic ratio), having the point A having a composition formula : (Al1-(x+z)TixMgz)N (X is 0.05 to 0.20; Z is 0.01 to 0.15) and having an interval between the adjacent point B and point A being 0.01 to 0.1μm. COPYRIGHT: (C)2004,JPO