Microstructure of laser-clad SiC-(Ni alloy) composite coating

The laser cladding technique was used to produce Ni alloy coatings with different SiC particle (SiCp) contents on steel 1045. The complete dissolution of SiCp took place during laser melting and led to a microstructural evolution of the coatings associated with the SiCp content. M7X3 or M23X6-type carboborides and Ni-base solid solution are found as the main microstructural constituents of the clad layers, and the volume fraction of the carboborides increases with increasing SiCp content. When the SiCp content reaches 30 vol.%, a silicide of Ni3Si2 phase and a few spherical graphite precipitates are observed, and the γ matrix shows a modulated structure. The addition of SiCp can significantly enhance the microhardness and wear resistance of the coatings.