The influence of alloying elements and heat treatment on the microstructure and mechanical behaviors of extruded Mg–Gd–Nd ternary alloys was investigated in this study. The grain sizes dramatically decreased after extrusion, and the particles which distributed in Mg matrix had great effect on the grain size. The grain sizes of extruded alloys decreased from 26 to 5 ​μm with the alloying content increasing. The mechanical test results show that both Gd and Nd had positive effect on the hardness, yield strength and Young's modulus. The ultimate tensile strength (UTS) was enhanced by Gd content, decreased with Nd content. The elongation of alloys was lower with higher alloying elements. Those extruded alloys were aged for 200 ​h in 200 ​°C. The Young's moduli were decreased by ageing treatment. Combined with microstructure study, the part of the reinforcement which identified as Mg₅(Gd/Nd) was dissolved in Mg matrix. Nd element obviously has influence on the solubility of Gd in Mg alloys.

本研究研究了合金元素和热处理对挤压 Mg-Gd-Nd 三元合金的显微组织和力学行为的影响。挤压后晶粒尺寸显着减小，分布在Mg基体中的颗粒对晶粒尺寸影响很大。随着合金含量的增加，挤压合金的晶粒尺寸从26μm减小到5μm。力学测试结果表明，Gd 和 Nd 对硬度、屈服强度和杨氏模量都有积极影响。极限抗拉强度 (UTS) 随 Gd 含量的增加而增加，随 Nd 含量的增加而降低。合金元素含量越高，合金的伸长率越低。这些挤压合金在 200°C 下时效 200 小时。杨氏模量因时效处理而降低。结合微观结构研究，₅ (Gd/Nd) 溶解在 Mg 基质中。Nd元素对Gd在Mg合金中的溶解度有明显的影响。