Patent ID: 6783725
Filing Date: 2004-08-31
Classification: C23C,Y10T

Abstract:
A method of machining a cast iron workpiece, the method comprising:providing a coated cemented carbide body insert, the coated cemented carbide body insert including a cemented carbide body, a first layer adjacent the cemented carbide body, the first layer including Ti(C,N) and having a thickness of from about 3 to about 20 &mgr;m, an alumina layer adjacent said first layer, the alumina layer including &agr;-Al2O3 and having a thickness of from about 1 to about 15 &mgr;m, a further layer adjacent the alumina layer, the further layer including a carbide, carbonitride or carboxynitride of one or more of Ti, Zr and Hf, the further layer having a thickness of from about 1 to 15 &mgr;m, and a friction-reducing layer adjacent to the further layer, the friction-reducing layer including one or more of &ggr;-Al2O3 and &kgr;-Al2O3, wherein the friction-reducing layer has a thickness of from about 1 to about 5 &mgr;m; contacting the coated cemented carbide body insert to the cast iron workpiece; and removing a portion of the cast iron workpiece in a turning operation.