An ultrathin melted layer on magnesium alloy manufactured by low power laser

Abstract

Low power Yb-fibre laser surface melting (LSM) was applied to modify the AZ31B magnesium alloy. The LSM treated samples presented poor formation qualities when the laser power was lower than 80 W. Samples without obvious macro-defects were obtained as the laser power higher than 88 W. The thickness of each melted layer was less than 125 μm. The grains of melted layer were refined and the solid solubility of aluminum increased. The average microhardness of the LSM treated samples was improved 37.7%. The corrosion resistance of LSM treated samples was raised by an order for magnitude and the wear resistance was improved 33% when the laser power was 104 W.