Effect of Heat Treatment on Microstructure and Tribocorrosion Performance of Laser Cladding Ni-65 WC Coating

The Ni-65wt%WC cladding layers were prepared on the surface of Q235 using laser cladding technology, in which the effect of heattreatment on microstructure and tribocorrosion performance was investigated. The results showed that the coating is mainlyconsisted of Ni, WC, and W2C, and a significant diffusion phenomenon is formed between the interfaces of WC/Ni matrix,benefited for the improvement of bonding layer between WC/Ni-based matrixes. Meanwhile, the crystallization of WC particlesafter heat treatment was more obvious than untreatment; the Ni matrix grain size was also grown remarkable, leading to thelower hardness and weaker plastic deformation resistance of Ni-65wt%WC coating. an‎d the erosion results showed that thewear rate of coating gradually decreased with heat treatment temperature increasing, while brittle WC was not suitable forhigh impact wear conditions. Furthermore, with the increase of heat treatment temperature, the reciprocating wearperformance showed that the friction coefficient and wear rate of Ni-65wt%WC coating decreased. an‎d the frictioncoefficient and wear rate of the coating (700°C) in 3.5% NaCl solution were 0.15 and4:82 × 10−8mm3·N-1·m-1, respectively.Therefore, the comprehensive comparison showed that Ni-65WC coating had better performance in low impactreciprocating testing under corrosion environment, and heat treatment was helpful to further improve the tribocorrosionperformance of laser cladding Ni-65wt%WC coating.