| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface coated cermet-made cutting tool, the hard coating layer of which exhibits excellent chipping resistance. SOLUTION: A hard coating layer of a tool base is composed of the following (a) and (b). (a) A lower layer is a Ti-compound layer formed of one or two or more layers formed by chemical vapor deposition, and (b) an upper layer is a thermal transformationαtype Al-Cr oxide layer having aκ-type orθ-type crystal structure in the chemical deposition formation state, in which the thermal transformation treatment is performed in the state where a Ti oxide layer satisfying a specified composition formula:TiO<SB>Y</SB>is formed on the surface of the Al-Cr oxide layer satisfying a specified composition formula:(Al<SB>1-X</SB>Cr<SB>X</SB>)<SB>2</SB>O<SB>3</SB>by chemical vapor deposition, thereby transforming the crystal structure of the Al-Cr oxide layer having theκ-type orθ-type crystal structure to theαtype crystal structure, the highest peak exists in the division of angle of inclination in the region of 0 to 10 degrees, and the total of the degrees existing in the region of 0 to 10 degrees occupies 45% or more of the whole degrees in the distribution graph of angle degrees of inclination. COPYRIGHT: (C)2006,JPO&NCIPI
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