Patent ID: 6406224
Filing Date: 2002-06-18
Classification: B22F,C22C,C23C,Y10T

Abstract:
A cutting tool for milling low and medium alloyed steels with or without abrasive surfaces during dry or wet conditions at high cutting speed, and milling hardened steels at high cutting speed, comprising:a cemented carbide body comprising WC, 7.1-7.9 wt-% Co and 0.2-1.8 wt-% cubic carbides of Ta, Ti and Nb, with Ti present on a level corresponding to a technical impurity, and a highly W-alloyed binder phase with a CW-ratio of 0.85-0.96: and a coating comprising: a first innermost layer of TiCxNyOz with x+y+z=1, z<0.5, with a thickness of 0.1-1.5 &mgr;m, and with equiaxed grains with a size <0.5 &mgr;m, a layer of TiCxNyOz with x+y+z=1, with z=0, x>0.3 and y>0.3, with a thickness of 1-8 &mgr;m, and with columnar grains with a diameter of about <5 &mgr;m, and a layer of a smooth, &kgr;-Al2O3 with a grain size of 0.5-2 &mgr;m and with a thickness of 0.5-5 &mgr;m.