The strain rate sensitivity (SRS) of binary Mg–Gd and Mg–Y alloys and the effect of solute on the rate-controlling mechanisms have been studied by analyzing rate changes during tension and compression tests at 78K and 298K. The steady-state SRS evaluated from the slope of Haasen plots at 78K increases with the solute concentration. The reverse behavior is observed at 298K, and the concentrated alloys exhibit the negative SRS. The activation work and the activation distance evaluated from strain rate jump tests at 78K discriminate regimes of plastic flow determined by solute–dislocation and dislocation–dislocation interactions. At the onset of plastic flow, dislocation–solute interactions control the plastic flow properties. This regime of low flow stress is represented by the activation work in the magnitude of $10^{-2}\mathrm{eV}$ and the activation distance in the range $10^{-2}$b - $10^{-1}$b. The deformation by mechanical twinning occurring early in the compression conforms to these parameters and suggest no fundamental difference in the thermally activated glide of ordinary and twinning dislocations through the field of solute obstacles. The results suggest that by-passing of Gd and Y atoms by basal dislocations occurs by sequential activation of partial dislocations. At higher flow stress, the dislocation–dislocation interactions determine the work-hardening. The thermally activated motion of jogs produced during interactions of basal and prismatic dislocations is thought to be the rate-controlling process. The activation work and the activation distance signatures of this process are W${}^{\ast }$ $\sim$ 0.4 eV - 0.8 eV and d $\sim$ 0.5b - 1b, depending on the solute content.

通过分析 78K 和 298K 拉伸和压缩试验期间的速率变化，研究了二元 Mg-Gd 和 Mg-Y 合金的应变速率敏感性 (SRS) 和溶质对速率控制机制的影响。从 78K 的 Haasen 图的斜率评估的稳态 SRS 随着溶质浓度的增加而增加。在 298K 观察到相反的行为，浓缩合金表现出负 SRS。从 78K 的应变率跳跃测试评估的活化功和活化距离区分了由溶质-位错和位错-位错相互作用确定的塑性流动状态。在塑性流动开始时，位错-溶质相互作用控制塑性流动特性。这种低流动应力状态由激活功的大小表示$10^{-2}\mathrm{电子伏特}$和范围内的激活距离$10^{-2}$乙 -$10^{-1}$湾。在压缩早期发生的机械孪晶变形符合这些参数，并且表明普通位错和孪晶位错通过溶质障碍场的热激活滑行没有根本差异。结果表明，基位错绕过 Gd 和 Y 原子是通过部分位错的顺序激活发生的。在较高的流动应力下，位错-位错相互作用决定了加工硬化。在基底位错和棱柱位错相互作用期间产生的微动的热激活运动被认为是速率控制过程。该过程的激活功和激活距离签名为 W${}^{*}$ $～$0.4 eV - 0.8 eV 和 d$～$0.5b - 1b，取决于溶质含量。