| 摘要 |
A cutting tool insert has cemented carbide body and coating. The cemented carbide body is consists of tungsten carbide with an average grain size of 1-2.5 mu m, 5-8, preferably 5-7 wt.% cobalt, and less than 0.5 wt.% cubic carbides of metals tantalum, titanium, and/or niobium; and a highly tungsten-alloyed binder phase. The cutting tool insert comprises cemented carbide body and coating. The cemented carbide body is consists of tungsten carbide (WC) with an average grain size of 1-2.5 mu m, 5-8, preferably 5-7 wt.% cobalt (Co), and less than 0.5 wt.% cubic carbides of the metals tantalum (Ta), titanium (Ti), and/or niobium (Nb); and a highly tungsten (W)-alloyed binder phase with a CW-ratio of 0.75-0.93 with less than 1 vol.% eta-phase. The coating comprises a first, innermost layer of TiCxNyOz (i), with x+y+z = 1; y is greater than x; and z is less than 0.2, preferably y is greater than 0.8 and z is zero, with equiaxed grains with size less than 0.5 mu m and a total thickness of 0.1-1.5 mu m; a layer of TiCxNy (ii) with x+y = 1; x is greater than 0.3, and y is greater than 0.3, preferably x >=0.5, with a thickness of 2-3 mu m with columnar grains with an average diameter of less than 5 mu m; a layer of a smooth, fine-grained, 0.5-2 mu m kappa-aluminum oxide with a thickness of 1-2.5 mu m; and an outer layer of titanium nitride (TiN) with a thickness of 0.5-1.0 mu m. An independent claim is also included for a method of making the inventive milling insert comprising: depositing by chemical vapor deposition (CVD) method a first, innermost layer of TiCxNyOz; depositing by MT(medium temperature)CVD-technique a layer of TiCxNy, wherein the MTCVD-technique uses acetonitrile as a source of carbon and nitrogen for forming a layer at 700-900[deg]C; depositing a layer of smooth kappa-aluminum oxide; and depositing an outer layer of TiN. |
