Study on the preparation and wear properties of laser cladded Incoel718/ WC gradient composite coatings

Laser cladding was employed to fabricate gradient coatings of Inconel718 + 10 wt%WC, Inconel718 + 30 wt% WC, and Inconel718 + 50 wt%WC on the surface of 42CrMo steel substrate, aiming to improve its wear resistance. The findings indicate that the Inconel718/WC gradient composite coatings have strong metallurgical bonding with the 42CrMo steel substrate. The Inconel718/WC gradient composite coating consists of gamma-(Ni, Fe), WC and W2C phases. The microstructure of the Inconel718/WC gradient composite coating mainly comprises planar crystals, columnar crystals, dendrites, and fine equiaxed dendrites, distributed from the bottom to the top. The hardness of the Inconel718/WC gradient composite coating shows a gradient distribution, with the topmost layer having an average hardness of 784.3 HV0.2, approximately 3.4 times that of the substrate. Compared to the substrate, the Inconel718/WC gradient composite coating demonstrates superior wear resistance, with the friction coefficient and wear mass loss rate reduced by 31.57 % and 76.19 %, respectively; the substrate exhibits adhesive wear, while the gradient coating shows abrasive wear. This research provides a valuable reference for the engineering application of 42CrMo steel as a structural material in additive manufacturing.