Co-Optimization of the Preparation Process of Ni-Based Self-Lubricating Coatings by Magneto-Thermal-Assisted Laser Cladding

To reduce the metallurgical defects that are prone to occur in the preparation of nickel-based self-lubricating coatings, a method of process co-optimization for magneto-thermal-assisted laser cladding of nickel-based self-lubricating coatings is proposed in this paper. The laser energy density, preheating temperature, and electromagnetic intensity are selected as input factors; the prediction models of coating dilution rate, porosity and microhardness are established by the CCD test method; the interactive effects of the magnetic-thermal-assisted cladding process on the coating response are analyzed, and the optimal process parameter combinations are obtained by using the optimization method of MOPSO-AE-TOPSIS. Finally, the coatings under the parameters are successfully prepared. The results show that the optimal process parameter combinations obtained are laser energy density of 56.8 J/mm2, preheating temperature of 350 °C, electromagnetic intensity of 49.1 mT, and the error of the experimental results with this parameter is less than 3% from the algorithm optimization results. When the microstructure of unassisted and magneto-thermal-assisted fields are analyzed by comparison, it is found that the tissues are more homogeneous and finer, and the distribution of graphite is more homogeneous, which proves the effectiveness of the optimization method.