| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool having a hard coating layer exhibiting superior chipping resistance in a high speed intermittent cutting work. <P>SOLUTION: The surface-coated cutting tool has a Ti compound layer as a lower part layer and a Zr-containing α-type Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>layer having a columnar crystalline structure formed by vapor deposition as an upper part layer. An outermost surface layer of the lower part layer is composed of a TiCN layer having a layer thickness of 500 nm or more and an average content of 0.5-3 atom% oxygen is contained only in a depth region up to 500 nm in the thickness direction of the TiCN layer. A lateral mean crystal grain diameter of the Zr-containing α-type Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>crystal grains disposed directly on the lower part layer is 0.1-0.3 μm. The lateral mean crystal grain size of the Zr-containing α-type Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>crystal grains on an upper side of the upper part layer is 0.5-1.0 μm. Furthermore, in the entire upper part layer of the Zr-containing α-type Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>crystal grains, Zr-containing α-type Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>crystal grains having an inclination angle of 0-10 degrees formed by the normal line of (0001) plane against the normal of a tool base surface have 45 area% or more in total, and less than 10% of a (0001) orientation and 30% or more of a (02-21) orientation within less than 1 μm of the film thickness of the upper part layer from the phase boundary. <P>COPYRIGHT: (C)2013,JPO&INPIT |
