| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool in which a hard coating layer demonstrates superior chipping resistance. <P>SOLUTION: The surface-coated cutting tool is configured such that (a) a lower layer, being a Ti compound layer containing at least a TiCN layer and (b) an upper layer, comprising an α type Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>layer are formed on the surface of a tool base body. In the TiCN layer of the lower layer, crystal grains TiCN ä110} having inclination angles of 0-10° range occupies 50% or more of all frequencies when an inclination angle frequency distribution graph is created by a normal of ä110} plane; and in the α type Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>layer of the upper layer, Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>(11-26) crystal grains having inclination angles within 35-45° range occupy 60% or more of all frequencies when the inclination angle frequency distribution graph is created by a normal of (0001) plane, and furthermore, when observed in a plane perpendicular to the layer thickness direction, a mean crystal grain size of the Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>(11-26) crystal grains is 2 to 5 times larger than that of crystal grains other than the Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>(11-26) crystal grains. <P>COPYRIGHT: (C)2012,JPO&INPIT |
