CAJ | 학술논문

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。
이용고능등리자속대AZ91D 미합금표면진행쾌속가열중용처리，병대중용층적현미조직、물상、경도이급내마내식성능진행분석。결과표명：재저방대배수하，중용층적조직위세소적지정，재고방대배수하，정립위세소적등축정립，척촌위5~7μm；여기체상비，물상조성잉위α-Mg화β-Mg17Al12，단α-Mg 상감소，β-Mg17Al12증가，차β-Mg17Al12상적분포경가균균미산；중용층적현미경도명현고우기체적현미경도；중용층랍신단구여기체랍신단구불동，유소성변형흔적이급유세소균균인와조성적섬유상적시렬흔，야유명현적정립발출흔적。등리자중용처리제고료AZ91D미합금적표면내마성화내식성능。
The surface of AZ91D magnesium alloy was remelted by plasma beam. The microstructure, composition, hardness, wear and corrosion resistance of the plasma remelted layer (PRL) were characterized. The results show that there is extremely fine and dendrite structure in the PRL at low magnification observation, which is still composed ofα-Mg andβ-Mg17Al12 phases. But at high magnification observation, the microstructure of the PRL is equiaxial crystalline grains with size of 3?5μm. And also the content ofα-Mg phase decreases while that ofβ-Mg17Al12 increases and distributes more uniformly inα-Mg matrix compared with the substrate. The hardness of the PRL is much higher than that of the substrate. There are plastic deformation, grains uprooting and tearing evidence with tiny even dimples in the tensile fracture of the PRL, which are different from the substrate. Furthermore, the surface wear and corrosion resistance of AZ91D are improved significantly after plasma remelting.