Parameter optimization and microstructure evolution of In-Situ TiC particle reinforced Ni-based composite coating by laser cladding

Laser cladding is one of the most effective ways of improving the abrasion resistance and corrosion resistance of surfaces and is thus widely used to reinforce steel surfaces. This study aimed to investigate the effects of laser parameters on the properties of the composite layer and the reinforcement of Ni-based composite powder on a steel surface by laser cladding. The laser cladding of Ni-based Ni60A+x%(SiC+Ti) composite powder on 45 steel surface to form TiC particle reinforced coating was evaluated by the preplaced-powder method. The effects of laser power and scanning speed on mechanical property and hardness were assessed. Microstructure, phase composition, and energy spectrum were comprehensively analyzed by scanning electron microscopy, X-ray diffraction, and energy-dispersive spectrometry, respectively. Results reveal that the use of composite powder to form a reinforced coating on the 45 steel is feasible. At 24% SiC+Ti content, a cladding layer with a compact and homogeneous microstructure is obtained at 800 W laser power and 125 mm/min scanning speed. Numerous dispersedly distributed TiC particles exist at the cladding layer, and the size and number of TiC particles gradually increase with increase SiC+Ti content. The findings in this study provide insight into the application and promotion of laser cladding on 45 steel materials. © 2018 Eastern Macedonia and Thrace Institute of Technology.