ANALYSES AND DESIGN OF A WC MILLING CUTTER WITH TICN COATING

The Taguchi method was employed to analyze and optimize titanium carbo nitride films on cemented carbide (WC-6% Co-10% TiC-8% TaC) indexable milling cutters with regard to machining conditions. Six variables-the film construction, cutting speed, feed rate, depth of cut, workpiece hardness and milling type-were considered. The results showed that the film construction was the most dominant variable, with a percentage c ontribution as high as 48.85% to the overall variance of the milling s ystem. Through calculations an optimal film construction was found to be 3 mu m TiN + 2 mu m TiCN (from the substrate to the top) rather tha n 5 mu m TiCN alone under the conditions specified in this study. The resultant flank wear achieved around 480% and 320% improvement compare d with the uncoated and 5 mu m TiN coated cutters. (C) 1998 Elsevier S cience S.A.