Influence of ball milling process on microstructure and properties of Ni-based coating by laser cladding

Ni50/(Ti, W)C composite coating was produced by laser cladding. The effect of ball milling process on the homogenization of coating microstructure and coating properties was studied. The microstructure, phase composition, microhardness, and wear resistance of the coating were investigated. The formation and growth of in situ synthesized ceramic particles were analyzed. The results showed that the coating presented a dense and homogeneous microstructure with few pores and no cracks. Ceramic particles (Ti, W)C were in situ synthesized in Ni-based coating. The fining of different kinds of powders can also lead to different microstructure of coatings. A large number of fine and irregular (Ti, W) C precipitated from the composite coating by laser cladding with ball milled Ti + W powder. When the composite powders were milled, the coating was not only reinforced phase, but also the matrix phase γ-(Fe, Ni) content increased. After laser cladding, the composite powders which only ball milling Ti + W powders, the microhardness and wear resistance of the composite coating were improved.