【摘要】 采用光学显微镜、X射线衍射仪、扫描电镜以及电子拉伸试验机等研究了不同热处理工艺及Zn元素对Mg-10Gd-3Sm（-1Zn）-0.5Zr（mass%）合金微观组织和力学性能的影响。结果表明：Zn元素的加入可以有效细化晶粒，促进第二相的析出，并生成一种新相（Mg, Zn）₃（Sm, Gd）₁;Mg-10Gd-3Sm（-1Zn）-0.5Zr合金的最佳热处理工艺为515℃×6 h固溶及225℃×10 h时效处理；对其进行室温和高温拉伸，发现随着温度的升高，时效态Mg-10Gd-3Sm（-1Zn）-0.5Zr合金的抗拉强度表现出先增大后减小的趋势；Zn的加入使合金的抗拉强度和伸长率明显高于基体合金，表现出优异的力学性能；两种合金在室温和高温下的断裂机制均属于脆性断裂，不含Zn的基体合金脆性特征更为明显，塑性较差，而含Zn的合金断口形貌中撕裂棱和解理刻面数目较多，塑性较高。更多还原

【Abstract】 Influence of different heat treatment processes and Zn element on microstructure and mechanical properties of Mg-10Gd-3Sm（-1Zn）-0.5Zr（mass%） alloys was studied using optical microscope, X-ray diffractometer, scanning electron microscopy, and electron tensile testing machine. The results show that the addition of Zn element can effectively refine the grain size, promote the precipitation of the second phase, and generate a new phase（Mg, Zn）₃（Sm, Gd）₁. The optimal heat treatment process for the Mg-10Gd-3Sm（-1Zn）-0.5Zr alloy is solution treatment at 515 ℃ for 6 h and aging at 225 ℃ for 10 h. It is found that with the increase of tensile temperature, the tensile strength of the aged Mg-10Gd-3Sm（-1Zn）-0.5Zr alloy shows a trend of first increasing and then decreasing when subjected to room temperature and high temperature tensile tests. The addition of Zn significantly increases the tensile strength and elongation of the alloy compared to the matrix alloy, resulting in excellent mechanical properties. The fracture mechanisms of both alloys at room temperature and high temperature belong to brittle fracture. The matrix alloy without Zn has more obvious brittle characteristics and poorer plasticity, while the alloy with Zn has more tearing edges and cleavage facets in the fracture morphology and higher plasticity.更多还原