Microstructure and wear property of laser cladding Al+SiC powders on AZ91D magnesium alloy

Al+SiC powders were pulse-laser (Nd–YAG) cladded on AZ91D magnesium alloy. The microstructure, chemical composition and phase analyses of the cladding layer were studied by scanning electron microscopy, EDX analysis, and X-ray diffraction measurement. The composite coating is composed of SiC and β-Mg17Al12 phases. The laser cladding showed very good bonding with the magnesium alloy substrate. The surface hardness of cladding coating is higher than that of substrate and increases with the increase of SiC content in the cladding. Sliding wear tests conducted in a pin-on-disc wear testing apparatus showed that the composite coating with SiC particles and in situ synthesized Mg17Al12 phase remarkably improved the wear resistance of the AZ91D magnesium alloy.