US Patent 7767319 Insert

The present invention relates to a coated cemented carbide milling insert for either wet or dry machining of cast iron such as nodular cast iron (NCI), grey cast iron (GCI), austempered ductile iron (ADI) and compacted graphite iron (CGI) where a high wear resistance and an excellent resistance against thermo cracks are required comprising:a substrate comprising from about 5 to about 7 wt-% Co, from about 140 to about 250 ppm Ti+Ta and balance WC with a weight ratio Ti/Ta of from about 0.8 to about 1.3 anda PVD-layer consisting of AlxTi1−xN, with x=from about 0.50 to about 0.70 and with a thickness of from about 1 to about 10 μm. The invention also relates to a method for making cutting tool inserts and their use.