Effect of laser remelting on the organization and properties of WC/Ni-based coatings generated in situ by laser cladding

In order to study the effect of laser remelting on the properties of H13 steel, WC/Ni-based coating was prepared on its surface by laser cladding. The macroscopic morphology, microstructure, element distribution and mechanical properties of the coatings before and after remelting were compared by means of scanning electron microscopy, energy spectrometer, XRD, hardness tester and friction and wear tester. The results show that the in-situ prepared cladding layer has no obvious defects such as cracks and pores. With the increase of laser energy density, the microstructure distribution in the remelted coating becomes more and more uniform, and the surface roughness of the coating becomes lower and lower. However, the microhardness and wear resistance of the coating have no obvious difference. When the laser energy density reaches 1500 J/mm, the ceramic particles inside the remelting coating basically disappear, the coating uniformity and surface smoothness are the best, the hardness reaches 768 HV0.5, and the wear resistance is 3.75 times that of the substrate.