The isothermal repetitive upsetting extrusion (RUE) was implemented to process ZK60 magnesium alloy at 380 °C. Then, the relationship between the microstructural characters, including grain refinement and texture evolution, and the mechanical performance of the alloy was investigated. Results showed that after 3 passes of RUE, the average grain size was refined from 115.0 to 26.5 μm, which was mainly caused by the continuous dynamic recrystallization and discontinuous dynamic recrystallization. Meanwhile, the elongation of the alloy increased from 13.8 to 21.6%, and the superplasticity (142%) of the alloy has been achieved in the following high temperature tensile test, which is very beneficial for the further processing of the alloy into components. In particular, the alloy formed a distinctive texture distributed between < 2-1-11 > and < 2-1-14 > , which was greatly related to the Schmid factor of extrusion direction (ED) and transverse direction (TD). This texture changed the initiation ability of basal and prismatic slip in both directions and inhibited the initiation of partial tensile twinning in TD; thus, the anisotropy in both directions was weakened. As expected, the tensile yield strength difference decreased from 25.9 to 3.4 MPa, but it was used as the cost of tensile yield strength in ED.

采用等温重复镦粗挤压 (RUE) 在 380 °C 下加工 ZK60 镁合金。然后，研究了合金的显微组织特征（包括晶粒细化和织构演变）与力学性能之间的关系。结果表明，经过3道RUE后，平均晶粒尺寸由115.0μm细化至26.5 μm，这主要是由连续动态再结晶和不连续动态再结晶造成的。同时，合金的延伸率从13.8%提高到21.6%，在随后的高温拉伸试验中达到了合金的超塑性（142%），这对合金进一步加工成部件非常有利。特别是合金形成了分布在<2-1-11>和< 2-1-14 > ，这与挤压方向（ED）和横向（TD）的施密德因子有很大关系。这种织构改变了基底和棱柱滑移两个方向的引发能力，抑制了TD局部拉伸孪生的引发；因此，两个方向的各向异性都减弱了。正如预期的那样，拉伸屈服强度差异从 25.9 MPa 降低到 3.4 MPa，但它被用作 ED 中拉伸屈服强度的成本。