The Effect of Different Laser Powers on the Properties of Ni65A Cladding Reinforced by WC

In this paper, the effects of different laser powers on the microstructure, microhardness, and wear resistance of Ni65A/WC composite coatings were investigated by using laser cladding technology. The morphology, phase structure, elemental distribution, wear behaviour, and property changes of the fused coatings were systematically characterised and analysed. The mechanism of power parameters on coating properties was summarised. The results show that different laser powers significantly affect the microstructure of the coating and the distribution of the enhanced phase WC. Under the 800 W power condition, the WC particles were not sufficiently dissolved and the organisation was not dense. The hardness and abrasion resistance were low. Under 1200 W power conditions, the enhanced phases were uniformly dispersed. The best microstructure densities and homogeneity were observed. The generated hard phase and matrix toughness achieved a good balance. The hardness of the coating reached 375 HV while also showing optimum wear resistance and stable friction behaviour. Under 1600 W power conditions, although the hard phase was completely dissolved and re-precipitated, some areas of tissue coarsening made the wear resistance slightly inferior to that at 1200 W. The 2000 W power condition resulted in a significant deterioration in the coating properties due to the increase in cracks and pores caused by the overheating of the melt pool. For this reason, 1200 W power conditions proved to be the ideal parameter range for optimising the microstructure and mechanical properties of Ni65A/WC composite coatings. The study in this paper can provide an important reference for the design of high-performance wear-resistant coatings.