(太原理工大学 机械工程学院，太原 030024)
摘 要: 通过OM、XRD、TEM、SEM和电子拉力试验机等，研究了固溶和时效处理对Mg-8Gd-2.5Nd-0.5Zr(质量分数，%)合金显微组织和力学性能的影响。结果表明：合金铸态组织由α-Mg 基体和含Mg5Gd相、Mg12Nd 相的粗大枝晶组成，经过热处理后，合金中方块状颗粒相明显增多，且分布在晶界处；固溶时效态合金析出的纳米尺寸方块相可有效强化合金。时效态合金中β′析出相形态类似多个纺锤形相连接而成，相互之间的夹角呈120°，且具有周期结构。铸态、固溶态和时效态合金在不同状态下的室温拉伸强度分别为：189.3、 201.4和251.1MPa。
关键字: Mg-8Gd-2.5Nd-0.5Zr合金；热处理；显微组织；力学性能
（College of Mechanical Engineering, Taiyuan University of Technology, Taiyuan 030024, China）
Abstract:Microstructure and mechanical properties of Mg-8Gd-2.5Nd-0.5Zr (mass fraction, %) alloy after solid solution and aging treatment were studied by OM, XRD, TEM, SEM and tensile experiment. The results show that the microstructure of as-cast alloy is composed of α-Mg matrix and crystal containing Mg5Gd and Mg12Nd phases. After heat treatment, more cuboid-shaped particles are founded. The nanoscale stripe phase is precipitated out, and the alloy is strengthened effectively. The β'''' phase of aged alloy is multiple spindle with periodic structure, and the mutual angle is 120°. The tensile strength of the alloy are 189.3MPa (as-cast), 201.4 MPa (solid solution state) and 251.1 MPa (aging state), respectively.
Key words: Mg-8Gd-2.5Nd-0.5Zr alloy; heat treatment; microstructure; mechanical property
