Tribomechanical behavior of TiCN/TiAlN/WC-C multilayer film on cutting tool inserts for machining

Condition of cutting tool determines the quality of machining operation performed on a material. Wear is the main phenomenon that deteriorates the tool life and indeed affects the quality of machined products. The research work deals with enhancing the wear resistance of tungsten carbide (WC) tool by mono- and multilayered film coating. The following WC-C/TiAlN/TiCN multilayered thin films were deposited on the surface of WC cutting tool insert using cathodic arc evaporation process. For comparison, monolayer TiAlN, TiCN and bilayer TiAlN/WC-C coatings were also prepared. Microhardness, surface roughness, wear behavior, frictional coefficient of uncoated and coated specimens were analyzed using Knoop & Vickers hardness tester, surface roughness tester, pin-on-disk wear tester, respectively. Multilayer coating comprising WC-C/TiAlN/TiCN exhibited lower friction coefficient, lower wear loss and higher hardness (25.83 GPa) compared to other thin film layered specimen and pure substrate (WC) owing to the presence of multilayer and hard layer. TiCN/TiAlN/WC-C multilayer coating exhibits lower coefficient of friction (COF) at a higher load (15 N) running for long distances (1900 m).