Wear resistance of AZ91D magnesium alloy processed by improved laser surface remelting

• A JW-CO2 continuous laser was employed to treat the surface of AZ91D Mg alloy. The laser surface remelting was carried out under water cooling condition.
• Two experimental parameters, the output power and the scanning speed, were investigated.
• The microstructures with different experimental parameters were characterized.
• The corresponding microhardness and resistance to wear were studied.

We investigate the effects of laser surface remelting on the wear resistance of the AZ91D magnesium alloy. A CO2 continuous laser was used to treat the samples. The sample surface was strengthened by laser-treated area in the shape of stripes. The wear resistance was improved by marked microstructural characteristics, due to the notable effect of laser treatment, such as the grain refinement and very small sized β-Mg17Al12 dendrite. The microhardness was increased up to 130 HV. And the wear volume loss was reduced by ~70%. The variations in some laser parameters, the output power and the laser scanning speed, also influenced the microstructure and related wear resistance.