Microstructure and Properties of Laser Cladding SiC Reinforced Ni35 Alloy Layer

20wt% SiC reinforced Ni35 alloy cladding layer was prepared on 45 steel surface by laser cladding at different laser power (1 000-1 400W) and scanning speeds (6-10 mm·s^-1). The optimal process parameters were determined according to the macromorpholgy of the cladding layer. The microstructure and properties of the cladding layer were studied under the optimal parameters. The results show that the optimal process parameters of the laser cladding layer were as follows: laser power of 1 000 W and scanning speed of 8 mm·s^-1. Under these parameters, the microstructure of the cladding layer consisted of dendrites and equiaxed crystals, and the phases included hard phases such as SiC, Ni₄B₃, CrB, Ni₂Si and FeSi. The hardness of the cladding layer was about 3.5 times that of the 45 steel substrate, and the hardness of the heat affected zone was higher than that of the substrate because of laser quenching effect during cladding. The wear mass loss of the cladding layer was obviously less than that of the substrate, and the increase in wear mass loss with the prolonged wear time was small, indicating that the wear resistance of the cladding layer was relatively good. The main wear mode of the cladding layer was adhesive wear after wear for 60 min, and was abrasive wear after wear for 120 min.