SURFACE-COATED HARD MATERIAL FOR CUTTING TOOLS OR WEAR RESISTANCE TOOLS

摘要

This invention relates to a surface-coated hard material for cutting tools or wear resistance tools, in which a coating layer is provided on the surface of a base material of a cutting tool or wear resistance tool to improve the wear resistance, characterized by providing a hard coating layer having a thickness of 0.5 to 10 .mu.m and consisting of at least one member selected from the group consisting of carbides, nitrides and carbonitrides of M1-x Alx (M represents Ti, Zr or Hf and 0 ~ x ~ 0.5) such that the composition ratio of M and Al is changed in stages or continuously from M of the boundary with the substrate to MAl of the outer surface at the opposite side to the substrate on the surface of a cutting tool or wear resistance tool.