SURFACE COATED SINTERED HARD ALLOY CUTTING TOOL HAVING EXCELLENT CHIPPING RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a surface coated sintered hard alloy cutting tool having excellent chipping resistance. SOLUTION: This cutting tool is constructed in such a manner that a hard coating layer including a Al2 O3 compound layer made mainly of Al2 O3 is vapor- deposited chemically and/or physically on the surface of a WC basic hard metal base body to have an average layer thickness of 3 to 20μm. The Al2 O3 compound layer contains, by weight, Zr and/or Hf: 0.5 to 10%, Cl: 0.005 to 0.1%, and N: 0.001 to 0.1%.