The effect of Zn addition on the microstructure and mechanical properties of Mg-9Gd-2Nd-0.5Zr alloys during equal channel angular pressing (ECAP) was investigated. Uniformly distributed dynamically recrystallized (DRXed) grains with an average grain size of 2.7 ± 0.3 μm were obtained in the ECAPed Mg-9Gd-2Nd-0.5Zr alloy. A large number of Mg₅RE phases were found to dynamically precipitate from the matrix, while the uniformly distributed dynamically recrystallized grains with an average grain size of 3.0 ± 0.3 μm were obtained in the Mg-9Gd-2Nd-1.6Zn-0.5Zr alloy. In addition, some coarse undynamically recrystallized (un-DRXed) grains existed due to the kinking of the long period stacking ordered (LPSO) phase. A small amount nano-β₁ phases were dynamically precipitated from the matrix with the exception of the broken (MgZn)₃RE and LPSO phase. The ECAPed Mg-9Gd-2Nd-1.6Zn-0.5Zr alloy expresses excellent comprehensive mechanical properties (YS = 321 MPa, UTS = 377 MPa, EL = 14.5%) compared with the Mg-9Gd-2Nd-0.5Zr alloy (YS = 317 MPa, UTS = 360 MPa, EL = 9.6%). This can be attributed to the strengthening and toughening effect of the LPSO phase, which not only makes the alloy exhibit a typical bimodal microstructure and improve the strength of the alloy, but also weakens the basal surface texture to improve the plasticity of the alloy.

研究了Zn添加对Mg-9Gd-2Nd-0.5Zr合金在等通道角挤压(ECAP)过程中显微组织和力学性能的影响。在 ECAPed Mg-9Gd-2Nd-0.5Zr 合金中获得了均匀分布的动态再结晶 (DRXed) 晶粒，平均晶粒尺寸为 2.7 ± 0.3 μm。发现大量Mg ₅ RE 相从基体中动态析出，而在Mg-9Gd-2Nd-1.6Zn-0.5Zr 合金中得到均匀分布的动态再结晶晶粒，平均晶粒尺寸为3.0±0.3 μm . 此外，由于长周期堆积有序（LPSO）相的扭结，存在一些粗大的非动态再结晶（非DRXed）晶粒。少量纳米_β1除了破碎的 (MgZn) ₃ RE 和 LPSO 相之外，其他相从基质中动态沉淀出来。ECAPed Mg-9Gd-2Nd-1.6Zn-0.5Zr 合金与 Mg-9Gd-2Nd-0.5Zr 合金 (YS = 317 兆帕，UTS = 360 兆帕，EL = 9.6%）。这可以归因于LPSO相的强韧化作用，不仅使合金呈现出典型的双峰显微组织，提高了合金的强度，而且削弱了基面织构，提高了合金的塑性。