Effect of rare earth La₂O₃ particles on structure and properties of laser cladding WC-Ni60 composite coatings

In the production of polysilicon, valve sealing surfaces are vulnerable to issues such as erosion wear from silicon powder, corrosion from chloride ions, and leakage leading to functional failure. This paper proposes a process route for laser cladding rare earth La2O3 doped Ni-based WC coatings on the surface of AISI 304 steel, and carries out a study on the macroscopic morphology, microstructure, physical phase evolution pattern, wear resistance and corrosion resistance of WC-Ni60 composite coatings from different particle sizes of rare earth La2O3. The results show that the addition of rare earth La2O3 optimized the macroscopic morphology and microstructure of WC-Ni60 coatings, and improved the wear and corrosion resistance of the coatings. Among them, micron-La2O3 showed the most significant improvement in the performance of WC-Ni60 coatings, with wear and self-corrosion current density reduced by 71.43 % and 59.63 %, respectively, compared with the substrate.