Patent ID: 6627049
Filing Date: 2003-09-30
Classification: B22F,C22C,C23C,Y10T

Abstract:
A method of making a cutting tool, the cutting tool comprising a WCâ€”Co based cemented carbide body comprising WC with an average grain size of about 1.4 &mgr;m, 12-13 wt-% Co and 0.4-1.8 wt-% TaC+NbC, and a W-alloyed binder phase with a CW-ratio of 0.82-0.91, the method comprising:applying a first innermost 0.1-0.5 &mgr;m bonding layer of TiN to the body; applying a second layer comprising a multilayered structure comprising a plurality of 0.05-0.2 &mgr;m thick sublayers of a composition (TixAl1-x)N in which x varies repeatedly between the two ranges 0.45xAl1-x)N adjacent to the TiN bonding layer having an x-value of 0.45xAl1-x)N having an x-value of 0.70applying a third 0.1-0.5 &mgr;m thick layer of (TixAl1-x)N, where x is 0.45applying a fourth outermost 0.1-0.2 &mgr;m layer of TiN; wherein the total coating thickness close to a cutting edge of the tool is in the range of 1-8 &mgr;m and the thickness of the second layer constitutes 75-95% of the total coating thickness.