Design and performance analysis of TiCN coated cemented carbide milling cutters

The Taguchi method was employed to analyse and optimise the use of TiCN films on cemented carbide (WC-6Co-10TiC-8TaC) indexable milling cutters with respect to machining conditions. Six variables, i.e. film construction, cutting speed, feedrate, 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 contribution as high as 46.10% to the overall performance of the milling system. Through statistical calculation an optimal variable combination was obtained, and the optimal film construction was found to be 3 μm TiN + 2 μm TiCN (from the substrate to the surface) rather than 5 μm TiCN alone. The resultant flank wear showed 380 and 280% improvement over the uncoated and 5 μm TiN coated cutters respectively.