In present work, the deformation behavior of AZ31 Mg alloy with surface mechanical attrition treatment (SMAT) had been studied. The microstructure and mechanical properties of AZ31 Mg alloy with SMAT were investigated. The results indicated that a gradient nanostructure could be formed in sample by SMAT, in which the grain size increased gradually from surface to matrix. A depth-dependent gradient microhardness was also formed due to the corresponding gradient microstructure. Yield strength and ultimate tensile strength of AZ31 Mg alloy with SMAT were significantly improved combining with decrease of fracture elongation. The effect of SMAT on anisotropy of mechanical properties of AZ31 alloy had been discussed and analyzed. The plastic anisotropy of the sample increased significantly after SMAT, which was related to the texture variation of rolled sheet and special deformation behavior of gradient nanostructure. Finally, in order to illuminate the difference in deformation behavior between fine and coarse grained microstructure, the in-situ tensile deformation behavior of AZ31 Mg alloy with one-side gradient structure had been studied by SEM. The deformation mechanism of AZ31 Mg alloy with gradient structure had been put forward.

在目前的工作中，研究了AZ31镁合金的表面机械磨损处理（SMAT）的变形行为。研究了带SMAT的AZ31镁合金的组织和力学性能。结果表明，通过SMAT可以在样品中形成梯度纳米结构，其中晶粒尺寸从表面到基体逐渐增大。由于相应的梯度微观结构，还形成了与深度有关的梯度显微硬度。结合SMAT的AZ31镁合金的屈服强度和极限抗拉强度显着提高，同时断裂伸长率降低。讨论并分析了SMAT对AZ31合金力学性能各向异性的影响。SMAT后，样品的塑性各向异性显着增加，这与轧制板的织构变化和梯度纳米结构的特殊变形行为有关。最后，为了阐明细晶粒组织和粗晶粒组织之间的变形行为差异，通过SEM研究了具有单侧梯度结构的AZ31镁合金的原位拉伸变形行为。提出了具有梯度结构的AZ31镁合金的变形机理。