| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface coated cutting tool with a hard coated layer exhibiting superior lubricating properties and wear resistance in high-speed heavy cutting of cast iron and carbon steel or others.SOLUTION: A surface coated cutting tool has an aluminum oxide layer having an average layer thickness of 0.2 to 5 μm and high in smoothness on an uppermost surface of a tool base body, the aluminum oxide layer comprises a spherical structure dispersed in a base material and into a base material, the base material is constituted of aluminum oxide crystal phase and amorphous phase, the spherical structure comprises an aggregate of one kind or two kinds of a needle-like crystal phase and a plate-like crystal phase and the amorphous phase, a ratio of an area occupied by the spherical structure included in a longitudinal cross section of the aluminum oxide layer is 20 to 60 area%, and a radius of an approximate circle is 0.02 to 0.5 μm. |
