镱对铝-镁合金显微组织和力学性能的影响

Influence of Yb on Microstructure and Mechanical Properties of Al-Mg Alloy

研究了Yb对Al-Mg合金显微组织和力学性能的影响。结果表明:添加0.3%(质量分数)Yb降低了Al-Mg合金的抗拉强度和屈服强度,主要是由于含Mg和Yb的化合物相的形成降低了Mg和Yb在Al基体中的固溶度,从而减小固溶强化效果。但添加1.0%Yb,基体中Yb溶质原子的浓度提高,产生很强的固溶强化效果,并提高热挤压制品的位错密度和加工硬化程度,改善合金的屈服强度和抗拉强度。

The effects of Yb on microstructure and mechanical properties of an extruded Al-Mg alloy were studied. The results indicated that the addition of 0.3% （mass fraction） Yb decreased the mechanical properties of the alloy, such as tensile strength and yield strength, since the formation of metallic com- pounds of Mg and Yb decreased the concentration of Mg and Yb atoms in A1 matrix so as to undermine the effect of solid solution strengthening. However, the addition of 1.0% （mass fraction） Yb substantially improved the mechanical properties of the alloy because the concentration of Yb solute atoms in A1 matrix was high enough to generate solid solution strengthening effect; the improvement of strength was also attributed to the large work-hardening and high dislocation density caused by the interaction between dislocations and Yb atoms.