利用高能等离子束对AZ91D镁合金表面进行快速加热重熔处理,并对重熔层的显微组织、物相、硬度以及耐磨耐蚀性能进行分析。结果表明:在低放大倍数下,重熔层的组织为细小的枝晶,在高放大倍数下,晶粒为细小的等轴晶粒,尺寸为5~7μm;与基体相比,物相组成仍为α-Mg和β-Mg17Al12,但α-Mg相减少,β-Mg17Al12增加,且β-Mg17Al12相的分布更加均匀弥散;重熔层的显微硬度明显高于基体的显微硬度;重熔层拉伸断口与基体拉伸断口不同,有塑性变形痕迹以及由细小均匀韧窝组成的纤维状的撕裂痕,也有明显的晶粒拔出痕迹。等离子重熔处理提高了AZ91D镁合金的表面耐磨性和耐蚀性能。 The surface of AZ91D magnesium alloy was rapidly heated and remelted by high energy plasma beam. The microstructure, phase, hardness and wear resistance and corrosion resistance of the remelted layer were also analyzed. The results show that the microstructure of the remelted layer is fine dendrites at low magnification, and the grains are fine equiaxed grains with a size of 5 ~ 7μm at high magnification. Compared with the matrix, the phase composition But still α-Mg and β-Mg17Al12, but α-Mg phase decreased, β-Mg17Al12 increased, and the distribution of β-Mg17Al12 phase more uniform dispersion; remelted layer of micro-hardness was significantly higher than the substrate hardness; Melt layer tensile fracture and the tensile fracture of the matrix is ​​different from the plastic deformation marks and formed by the tiny homogeneous dimples of fibrous tear, there are obvious signs of grain pull out. Plasma remelting treatment improves the surface wear resistance and corrosion resistance of AZ91D magnesium alloy.