CEMENTED CARBIDE-MADE CUTTING TOOL WITH SURFACE CLAD WHOSE RIGID CLAD LAYER EXERTS EXCELLENT CHIP LUBRICATION- ABILITY

摘要

PROBLEM TO BE SOLVED: To provide a cemented carbide-made cutting tool with a surface clad by which a rigid clad layer exert excellent chips lubrication-ability. SOLUTION: This cutting tool is made by physical-vapor-depositing the rigid clad layer comprising (a) a lower layer comprising either or both of the layer of Ti-Al-based composite nitride having a structure in which the fine grains of zirconium oxide are dispersedly distributed at the rate of 0.3-15 by mass % on the untreated surface of Ti-Al nitride shown by a composition formula: [Ti1- XAlX]N, and the layer of Ti-Al- based composite nitro-carbide having the structure in which the fine grains are dispersedly distributed at the rate of the same amount as (a) on the untreated surface comprising Ti-Al nitro-carbide shown by a composition formula: [Ti1- XAlX]C1-m Nm , and having an average layer thickness of 0.5-15μm, and (b) an upper layer comprising the layer of Al-based composite nitride having a structure in which the fine grains of zirconium oxide are dispersedly distributed at the rate of 0.3-15 by mass % on the untreated surface comprising aluminum nitride and having the same average layer thickness as (a) on the surface of the basic body of a tool made by cemented carbide or cermet.