Improving room temperature ductility and formability is a bottleneck for a wide industrial application of Mg alloys, but even the mechanism for the effect of alloying elements on the deformation behavior of Mg is not clearly known. Here, using a molecular dynamics simulation, we clarify the role of alloying elements in improving the room temperature ductility of Mg alloys: Solute atoms have stronger dislocation binding tendency and solid solution strengthening effect on basal <a> slip planes than on non-basal <c+a> slip planes, reduce the anisotropy in the critical resolved shear stress between slip systems, and eventually improves the room temperature ductility. We predict that any solute elements with a size difference from Mg can improve the room temperature ductility, once the alloying amount is carefully controlled. By proving the validity of the prediction experimentally, we provide a new guide for designing Mg alloys with improved room temperature ductility and formability.

室温延展性和可成形性的提高是镁合金在工业上广泛应用的瓶颈，但是，甚至合金元素对镁变形行为的影响机理也不清楚。在这里，通过分子动力学模拟，我们阐明了合金元素在改善Mg合金的室温延展性中的作用：溶质原子对基<a>滑移平面比非基体<a>具有更强的位错结合趋势和固溶强化作用c + a>滑移平面，减小了滑移系统之间的临界解析切应力中的各向异性，并最终提高了室温延展性。我们预测，一旦小心控制合金化量，任何与Mg大小相差较大的溶质元素都会改善室温延展性。