| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a cutting insert which includes a base material and a coating film, and can be used in milling a very highly alloyed gray cast iron, and further to provide its manufacturing method. <P>SOLUTION: The cemented carbide base material is composed of WC, 3 to 8 wt.% of Co, and less than 0.5 wt.% of carbide of group IVb, Vb or VIb metals in the periodic table. The coating film includes a first innermost layer of TiC<SB>x</SB>N<SB>y</SB>O<SB>x</SB>, wherein x+y+z=1, y>x and z<0.2, preferably y>0.8 and z=0, the first innermost layer having equi-axial grains having a size of less than 0.5μm and a total thickness of 0.1 to 1.5μm; a layer of TiC<SB>x</SB>N<SB>y</SB>, wherein x+y=1, x>0.3 and y>0.3, preferably x>0.5, the layer having cylindrical grains having a mean diameter of less than 0.5μm and a thickness of 3 to 5μm; a layer ofκAl<SB>2</SB>O<SB>3</SB>having a thickness of 0.5 to 3μm, preferably 0.5 to 2μm, the layer having smooth and beautiful fine grains having a grain size of 0.5 to 2μm; and an outermost layer of TiN having a thickness of less than 2μm, preferably 0.5 to 1.5μm. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
