Microstructure and properties of plasma remelted AZ91D magnesium alloy  

AZ91D镁合金等离子束重熔组织与性能(英文)

作　　者：崔洪芝[1] 孟兆涛[1] 肖成柱[1] 孙金全[1] 王翠香[1] 

机构地区：[1]山东科技大学材料科学与工程学院,青岛266590

出　　处：《Transactions of Nonferrous Metals Society of China》2015年第1期30-35,共6页中国有色金属学报（英文版）

基　　金：Projects(51072104,51272141)supported by the National Natural Science Foundation of China;Project(ts20110828)supported by the Taishan Scholars Project of Shandong Province,China;Project(2015AA034404)supported by the Ministry of Science and Technology of China

摘　　要：The surface of AZ91 D 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 of α-Mg and β-Mg17Al12 phases. But at high magnification observation, the microstructure of the PRL is equiaxial crystalline grains with size of 3-5 μm. And also the content of α-Mg phase decreases while that of β-Mg17Al12 increases and distributes more uniformly in α-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 AZ91 D are improved significantly after plasma remelting.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。

关 键 词：magnesium alloy plasma remelting solid solution strengthening refined crystalline strengthening wear resistance corrosion resistance 

分 类 号：TG146.22[一般工业技术—材料科学与工程]