采用X线衍射仪、光学显微镜、扫描电镜和透射电镜等分析测试方法研究Er对Mg-3Nd-0.2Zn-0.4Zr(NZ30K)合金时效态组织和腐蚀性能的影响,研究结果表明:添加0.5％(质量分数)Er元素并没有改变NZ30K合金峰时效析出相的种类,2种合金在200℃时达到峰时效都是因为基体里析出大量弥散分布的β"相,起到第二相强化的作用,β"相具有密排六方DO19结构,其与基体的取向关系为[(2)4(2)3]β"//[2423]a-Mg,(1010)β"//(10(1)0)a-Mg;由于细小的β"强化相的弥散分布,2种合金时效态表面由紧凑和均匀分布的细长条状颗粒组成,主要为Mg(OH)2,NZ30K-Er合金时效态的腐蚀产物膜更致密,所以NZ30K-Er合金时效态的耐腐蚀性能好于NZ30K合金时效态的耐腐蚀性能；NZ30K合金时效态具有优良的耐腐蚀性能,在5％的NaCl溶液中,其腐蚀电流密度仅为8.012 μA/cm2,腐蚀质量损失速率仅为0.243 mg/(cm2·d).%The effects of Er addition on microstructure and corrosion properties of Mg-Nd-Zn-Zr alloy were investigated by X-ray diffractometry (XRD), optical microscopy(OM), scanning electron microscopy(SEM), transmission electron microscope(TEM) etc. The results show that the addition of 0.5% Er does not change the type of precipitated phase in NZ30K alloy's peak-aged process. The reason why the two alloys reach their peak-aged hardness at 200 ℃ is that the precipitation of many uniform and homogeneously distributed fine β" phase in the Mg matrix, β" phase has a strengthening effect on Mg matrix and it has hep DO19 structure. And its oriented relationships with Mg matrix is [2423]β//[2423]a_Mg, (10l0)β-//(10l0)a_Mg Because of the homogeneous distribution of fine β" phase, the surface of both alloys is covered by compact and homogeneously distributed band-shaped fine particles(mainly Mg(OH)2), the corrosion product film of NZ30K-Er aging state is more compact, and so the corrosion resistance properties of NZ30K-Er aging state is better. NZ30K-Er aging state has an excellent corrosion resistance property. Immersed in 5% NaCl solution, NZ30K-Er alloy's corrosion current density is only 8.012 μA/cm2 and its corrosion mass loss rate is just 0.243 mg/(cm2d).
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