Mg-Al-Zn合金的成分、组织与性能的关系研究

Study on Relations among the Composition, Microstructure and Properties of Mg-Al-Zn Alloys

在ZM5镁合金的基础上,添加部分Zn元素和少量Ag元素,研究了新合金与ZM5合金组织及性能的差异,探讨固溶和时效处理对Mg Al Zn合金中组织演变的影响以及组织与性能之间的关系。结果表明:在ZM5合金中添加Zn能较为明显地增加合金中的γ(Mg17Al12)相的数量,且使之变得较为粗大,片层的取向也显得比较复杂多样,而且合金在T4(固溶)和T6(固溶+时效)状态下的屈强比也有较为明显的提高,而延伸率降低;热处理状态对Mg Al Zn合金的显微组织有明显的影响;固溶处理后的时效处理能明显提高Mg Al Zn合金屈强比;分布在基体晶界处的γ相的数量、大小和形态与合金的拉伸性能有着密切的关系。

Some of Zn and a little Ag are added into ZM5 magnesium alloy. On this basis, this paper studies the difference of the microstructures and properties between the new alloy and ZM5 and discusses the effect of solid solution and aging treatment on the microstructure of Mg-AI-Zn alloys and the relation between microstructure and properties. With the addition of the alloying element Zn, the amount and size of Y (Mg17Al12) phase increase with more complicated orientations of the slices, and the value of YS/UTS increases quite obviously while the elongation decreases in both conditions of T4 (solid solution) and T6 (solid solution + aging). The effect of heat-treatment on microstructure is remarkable, and the aging treatment after solid solution can obviously increase the value of YS/UTS of Mg-Al-Zn alloys. The amount, size and shape of Y phase at the grain boundary have close relation to the tensile properties.