| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool whose hard coating layer exhibits excellent chipping resistance during high-speed intermittent cutting. <P>SOLUTION: There is provided the surface-coated cutting tool in which a lower layer formed of a Ti compound layer and an upper layer formed of an Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>layer are formed by coating on a surface of a tool base body. Tilt angles formed between a normal line of the tool base body surface and normal lines of (0001) faces of a crystal grain are measured for Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>grains of the upper layer, and when an angle difference between measured tilt angles of adjacent measurement points is 5°or larger, grains of these points are determined to be mutually different crystal grains and the crystal grains are specified. When aspect ratios of the individual crystal grains are obtained, the area ratio of crystal grains of less than 5 in aspect ratio is 10-50% and the area ratio of crystal grains of not less than 5 in aspect ratio is 50-90%. When in-crystal-grain average orientation differences of the individual crystal grains are found, an average of the in-crystal-grain average orientation differences of crystal grains of less than 5 in an aspect ratio is less than 5°and an average of the in-crystal-grain average orientation differences of crystal grains of not less than 5 in an aspect ratio is not less than 5°. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
