Tool life performance of multilayer hard coatings produced by HTCVD for machining of nodular cast iron

In this study, tool life performance of multilayer hard coatings was evaluated for machining of nodular cast iron. With this regard, TiCN+TiC+TiCN+Al2O3+TiN and TiCN+TiC+TiCN+Al2O3+TiN multilayered coatings with different thicknesses were fabricated on WC substrates using high temperature chemical vapor deposition (HTCVD). These cutting tools with hard multilayered coating systems were used in longitudinal turning of nodular cast iron under cutting condition encountered in the shop floor. To investigate the tool life performance in cutting tools coated by HTCVD method, cutting experiments were performed in CNC turning bench by using three distinct cutting tools having multilayered hard coatings and WC insert with square edges, and two types of nodular cast irons. Cutting speed, depth of cutting, and feed rate were kept as constant values. Tool life based on flank wear was the parameters considered to compare the three cutting tools. It was found that TiCN+TiC+TiCN+Al2O3+TiN (T3) multilayer coating with 10.5 μm thick exhibited better performance according to all parameters.