Effects of tailored gradient interface on wear properties of WC/Inconel 718 composites using selective laser melting

The WC/Inconel 718 composites were fabricated by selective laser melting (SLM). The laser processing parameters played an important role in determining the microstructure and performance of the WC/Inconel 718 composite parts. With the decrease in the laser scanning speed, the densification rate increased and achieved 97.8% at a scanning speed of 350 mm/s. As an optimal scan speed of 450 mm/s was applied, the WC/Inconel 718 composite part obtained a mean microhardness as high as 393.2 HV0.1. At the same time, a regular and orderly gradient interface with a mean thickness of 0.27 μm surrounded by a diffusion layer was obtained. What is more, the chemical composition of the gradient interface and the diffusion layer were X3C17 and XC4 (X = W, Ni, Cr, Fe), respectively. Meanwhile, the composite acquired a considerably low coefficient of friction (COF) of 0.35 with almost no fluctuation and attendant wear rate of 2.5 × 10− 4 mm3 N− 1 m− 1 and the wear mechanism changed continuously from severe abrasive wear to adhesive wear. Subsequently the effects of the tailored gradient interface on wear performance were discussed. It revealed that the existence of gradient interface showed a very important role in improving the wear performance of the SLM-processed WC/Inconel 718 composite parts.