| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool having a hard coating layer exhibiting excellent chipping resistance in high-speed intermittent cutting machining. <P>SOLUTION: In the surface-coated cutting tool having the hard coating layer comprising a lower layer, an intermediate layer and an upper layer formed on the surface of a tool substrate by vapor deposition: (a) the lower layer is composed of a Ti compound layer; (b) the intermediate layer is composed of a Zr-containing κ-type Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>layer (lower intermediate layer) containing 0.004-0.12% (where a ratio of Zr relative to the entire composition is expressed by atom%) of Zr in the Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>layer of a κ-type crystal structure, and a ZrO<SB POS="POST">2</SB>thin layer (upper intermediate layer) partially formed on the surface of the lower intermediate layer; and (c) the upper layer, when observing its vertical cross section, has an α-κ mixed structure of a κ-type Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>phase and an α-type Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>phase formed on the ZrO<SB POS="POST">2</SB>thin layer, and furthermore, the upper layer, when observing its surface-polished surface, comprises an Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>layer having an α-κ mesh-like mixed structure in which the κ-type Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>phase surrounds the periphery of the α-type Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>phase. <P>COPYRIGHT: (C)2013,JPO&INPIT |
