Rich Al infiltration layer on AZ91 D magnesium alloy surface was prepared synchronously in die casting process by surface infiltration technology. Thickness

microstructure and micro-area composition in the infiltration layer were analyzed. The results show that the rich Al infiltration layer exhibits metallurgical bonding with the matrix. With increasing in thickness of coated Al powder on surface of mould

infiltration layer on the magnesium alloy surface becomes continuous and compact with thickness increase

however

change of chemical composition in micro-area shows slightly. Al content in infiltration layer is decreased gradually from surface to inner layer.