Effect of laser surface melting on microstructure and corrosion characteristics of AM60B magnesium alloy

Surface modification of laser surface melting (LSM) was applied to the AM60B magnesium alloy using a 10 kW continuous-wave CO2 laser. The microstructure, composition and corrosion resistance of AM60B magnesium alloy after LSM treatment were investigated by using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD) and corrosion tests, respectively. Results showed that the LSM treatment produced a continuous and homogeneous modified layer with refined grains, enriched Al element and redistributed intermetallic compounds on AM60B alloy. The corrosion resistance of the AM60B alloy was enhanced by the LSM treatment. The enhancement of the corrosion resistance was mainly attributed to the reduced corrosion susceptibility of Al enriched α-Mg matrix and the barrier effect of uniformly distributed β-phase of the LSM modified layer.