An investigation on wear and cavitation erosion-corrosion characteristics of the TiC modified Fe-based composite coating via laser cladding

Fe-based composite coating, modified with TiC ceramic particles, has been successfully manufactured on 304 stainless steel substrate by laser cladding technique in this paper. The phase distribution and microstructure of composite coating are carefully studied via some advanced techniques such as XRD, SEM, EDS and EBSD, meanwhile, the microhardness, wear resistance, electrochemical performance and cavitation corrosion resistance of composite coating and substrate are systematacially tested. The obtained results reveal that the as-cladded composite coating is mainly composed of α-Fe, (Cr,Fe)7C3 and TiC. The introduction of TiC particles refined the microstructure inside the dendrites, at the same time the different forms of TiC particles are dispersively distributed in the composite coating. It is found the high microhardness is beneficial for the wear resistance of the coating. Compared with the matrix and some common engineering materials, although no obvious passivation zone is observed, the composite coating also exhibits superior electrochemical performance. Combining the excellent electrochemical and mechanical properties of the coating, the cavitation corrosion resistance of the composite coating has been significantly enhanced. A cavitation erosion resistance mechanism for composite coating has been proposed.