SURFACE COVERED CEMENTED CARBIDE CUTTING TOOL HAVING HARD COVERING LAYER EXHIBITING SUPERIOR CHIPPING RESISTANCE UNDER HIGH SPEED HEAVY DUTY CUTTING CONDITION

摘要

PROBLEM TO BE SOLVED: To provide a surface covered cemented carbide cutting tool having a hard covering layer exhibiting a superior chipping resistance under high speed heavy duty cutting conditions. SOLUTION: A complex nitrides layer of Al, Ti, and Mg of 1-15μm in the whole average layer thickness is physically vapor-deposited on the surface of WC-based cemented carbide alloy base or titanium carbonitride based cermet base. A component concentration distribution structure is so formed that an Al maximum containing point (hereinafter, refers to as A point) and a Al minimum containing point (hereinafter, refers to as B point) are alternately repeated at a prescribed interval and Al contents are continuously changed from the A point to the B point and from the B point to the A point respectively. The hard covering layer is so formed that the A point satisfies a composition formula: (Ti1-(X+Z)AlXMgZ)N (wherein X shows 0.45-0.60 and Z shows 0.01-0.15 in an atom ratio), the B point satisfies a composition formula: (Ti1-(X+Z)AlXMgZ)N (wherein X shows 0.10-0.25 and Z shows 0.01-0.15 in the atom ratio) and the interval between the adjoining A point and the B point is set to 0.01-0.1μm. COPYRIGHT: (C)2004,JPO