Microstructure evolution of the laser surface melted WC-Ni coatings exposed to cavitation erosion

Abstract

In this study, WC-Ni coatings were deposited using cold spraying followed by laser surface melting to improve the cavitation erosion resistance. The remelted coating presented a three-dimensional WC skeleton structure which could be regulated. The remelted coatings with uniformly distributed WC skeleton exhibited remarkable cavitation erosion resistance. The observed microstructure evolution in the remelted coatings during cavitation erosion suggested that the WC skeleton prevented crack propagation and therefore enhanced the cavitation erosion resistance. Results also indicated that the enhanced cavitation erosion resistance of the remelted coatings was attributed to the synergistic effect of the Ni binder phase and the hard WC phase. Adjusting and controlling the structure of the coatings allowed the WC-based coatings to exhibit excellent cavitation erosion resistance.