Microstructure and Properties of Inconel 718/WC Composite Coating on Mold Copper Plate

In order to improve the high-temperature wear resistance of mold copper plates, this study used laser cladding technology to prepare a high-wear-resistant composite coating with Inconel 718 and WC(Tungsten carbide) particles. The phase composition, microstructure, microhardness, and tribological properties at 400 °C were systematically analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Vickers microhardness tester, and high temperature friction and wear tester. The results indicate that the Inconel 718/WC coating is free of pores and cracks and exhibits a metallurgical bond with the substrate. Its phases mainly consist of a γ-Ni solid solution and various hard carbide reinforcing phases, such as MC, M3W3C, and W2C. The average microhardness of the coating reaches 851.7 HV0.5, which is 11.5 times than that of the substrate (74 HV0.5). At 400 °C, the wear rate of the coating is 3.48 × 10−4·mm3·N−1·m−1, only 35.7% of the substrate’s wear rate. The dominant wear mechanism is abrasive wear, accompanied by oxidative wear. The outstanding performance of the coating is attributed to the combined effects of grain refinement strengthening, solid solution strengthening, and second-phase strengthening induced by the various hard carbides.