Assessment of parameter sensitivity during laser cladding of Ni-WC composite coating under alternating magnetic field

The alternating magnetic field can significantly improve the quality of laser cladding Ni-WC coatings, including enhancing uniformity, refining grains and increasing efficiency. Quantitative evaluation of the process parameter sensitivity in the alternating magnetic field is significant for optimizing the laser cladding quality. In this article, a three-dimensional numerical model during laser cladding of Ni-WC composite coating with the aid of alternating magnetic field was established. The effects of alternating magnetic field on heat transfer, fluid flow and stress were calculated and analyzed, and the transient evolution of multi-field coupling during the cladding process was revealed. The response surface model was established based on BBD method, and sensitivity analysis was carried out in combination with Monte-Carlo. The calculation results show that the alternating magnetic field slightly reduces the temperature and stress of the cladding layer, and increases the flow velocity of the molten pool to 0.21 m/s. The sensitivity analysis shows that the influence of laser power is the most significant. Experimental verification shows that the height simulation error of the cladding layer is only 3.6%, and the hardness increases by 4.4% under the alternating magnetic field. This confirms that the magnetic field can effectively improve the WC distribution uniformity and significantly enhance the mechanical properties.