In order to obtain higher synthetically mechanical properties, Mg-4Al-1Si-1Gd alloy was deformed by the combination of hot extrusion and equal channel angular pressing (ECAP). The results show that combined deformation process can further promote grain refinement of Mg-4Al-1Si-1Gd alloy, so that Mg₂Si phase distributes more uniformly and induce the precipitation of Mg₁₇Al₁₂ particles. With the addition of subsequent ECAP, the grain size of the alloy was reduced from 10.68 ± 0.2 μm to 2.48 ± 0.1 μm. After the hot extrusion at 300 ℃ and two passes ECAP at 200 ℃, the short rod-like Mg₂Si phase was broken and evenly distributed in the matrix. Remarkably, a large number of sub-microns Mg₁₇Al₁₂ precipitation particles along the grain boundaries were observed, and the average particle size was 0.43 ± 0.05 μm, which can inhibit grain growth to promote grain refinement. And Mg₁₇Al₁₂ precipitation particles can be able to prevent the dislocation from moving in view of the Orowan mechanism. At the same time, the broken Mg₂Si particles with uniform distribution can enhance the elongation of alloy by reducing the crack source. Therefore, the optimum mechanical properties can be obtained. Specifically, the tensile strength is 293.8 MPa, the yield strength is 241.5 MPa and the elongation reaches 30.1%.

为了获得更高的合成机械性能，Mg-4Al-1Si-1Gd合金通过热挤压和等通道角挤压（ECAP）的结合而变形。结果表明，组合变形过程可以进一步促进Mg-4Al-1Si-1Gd合金的晶粒细化，使Mg ₂ Si相分布更均匀，并引起Mg ₁₇ Al ₁₂颗粒的析出。通过添加后续的ECAP，合金的晶粒尺寸从10.68±0.2μm减小到2.48±0.1μm。在300℃热挤压后，在200℃两次通过ECAP，短棒状Mg ₂ Si相破碎并均匀分布在基体中。值得注意的是，大量的亚微米Mg ₁₇ Al ₁₂观察到沿晶界的沉淀颗粒，平均粒径为0.43±0.05μm，可抑制晶粒长大，促进晶粒细化。考虑到Orowan机理，Mg ₁₇ Al ₁₂沉淀颗粒能够防止位错移动。同时，破碎的Mg ₂ Si颗粒具有均匀的分布，可以通过减少裂纹源来提高合金的延伸率。因此，可以获得最佳的机械性能。具体而言，抗拉强度为293.8MPa，屈服强度为241.5MPa，伸长率达到30.1％。