| 摘要 |
A cutting tool insert comprises: (a) a cemented carbide body of WC, 6-15 (9-12) weight % Co and 0.2-1.8 weight % cubic carbides of Ti, Ta and/or Nb, and a highly W-alloyed hinder phase with a CW ratio of 0.78-0.93 (0.8-0.91); and (b) a coating comprising an innermost TiCxNyO2 1.5~mm thick with equiaxed grains 0.5~mm, a 2-5~mm thick TiCxNyO2 layer with columnar grains with an average diameter 5~mm, and an outer layer of smooth fine-grained (0.5-2 ~mm) k-Al2O3 0.5-6 ~mm thick. The manufacture of the insert is also claimed and comprises forming the innermost layer of TiCxNyO2 by known CVD methods (x+y+2=1, z0.5) to a thickness of 0.1-1.5~mm, forming the 2nd TiCxNyO2 layer by MTCVD using acetonitrile as the C and N source at 850-900 deg.C (x+y+z=1, 2 = preferably 0, x>0.3 and y>0.3, and forming a TiN layer 1~mm on the k-Al2O3 layer. |
