Effects of laser energy on the surface quality and properties of electrodeposited zinc-nickel-molybdenum coatings

As a substitute for toxic cadmium coatings in the aerospace industry, zinc-nickel coatings have excellent application prospects, and their properties can be improved by adding molybdenum. In this study, laser-assisted electrodeposition is used to improve the surface quality and properties of Zn–Ni–Mo coatings, with investigation of how laser energy in the range of 0–21.1 μJ affects their element content, surface morphology, crystal phase, microhardness, residual internal stress, and corrosion resistance. The laser irradiation accelerates the electrodeposition, refines the grain size, improves the hydrogen adsorption, and reduces the residual tensile stress, and a laser energy of 15.4 μJ gives the highest Ni and Mo contents and the lowest Zn content, as well as the optimum surface morphology, microhardness, residual internal stress, and corrosion resistance of the coating.