Effect of WC composition on the microstructure and surface properties of laser directed energy deposited SS 316-WC composites

This paper reports an investigation on SS 316-tungsten carbide (WC) composites built using laser-directed energy deposition by varying the WC volume fraction from 6 to 10%. The built structures are subjected to characterization to investigate the effect of WC on the relative density, microstructure, microhardness and tribological properties of SS 316-WC composites. It is observed that the relative density of composite reduces with an increase in the volume fraction of WC particles. The microstructure is primarily dendritic, and XRD analysis revealed the presence of WC and γ
Fe phases with minimum crystallite size of 18.82 nm at 10% of WC in SS 316. The improvement in corrosion resistance is identified with the addition of WC, and least current density of 1.47μAcm2
is identified with 8% of WC. The microhardness of composite is observed to increase with an increase in the WC content and the wear rate is observed to reduce with an increase in WC content. Maximum hardness of 399.5 HV0.98N and minimum wear rate of 0.03107 × 10−4 mm3/Nm are obtained at 10% of WC. Scanning electron microscopy images indicate the presence of parallel grooves, wear debris and plastic deformation on the wear tracks