Synergistic effects of solutes on active deformation modes, grain boundary segregation and texture evolution in Mg-Gd-Zn alloys
Synergistic effects of solutes on active deformation modes, grain boundary segregation and texture evolution in Mg-Gd-Zn alloys
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DOI：
10.1016/j.msea.2022.143348
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发表时间：
2022-05
期刊：
影响因子：
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通讯作者：
F. Mouhib;R. Pei;B. Erol;F. Sheng;S. Korte-Kerzel;T. Al-Samman
中科院分区：
文献类型：
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作者：
F. Mouhib;R. Pei;B. Erol;F. Sheng;S. Korte-Kerzel;T. Al-Samman
稀土元素与Zn的协同作用对三元Mg-RE-Zn合金的性能有重要影响。本研究阐明了它们的依赖于溶质比通过比较织构演变，溶质偏析，和主动变形模式的三个Mg-Gd-Zn合金与不同的Gd：Zn比为2：1，1：1和1：2。一个低的Gd：Zn比导致纹理具有显着的TD倾斜的基底极扩展旁边的放大溶质偏析在晶界，表明显着影响溶质-边界相互作用的RE织构形成。原子探针断层扫描显示Gd和Zn的偏析能量的重大改变，主要取决于溶质比，而不是绝对的溶质浓度。此外，具有最小Gd：Zn比（即Gd：Zn = 1：2）的合金在拉伸应变下表现出最高的屈服应力的方向相关各向异性，这归因于取决于Gd：Zn比的孪晶的放大的各向异性。EBSD辅助滑移痕迹分析表明，非基底滑移系统的出现可以通过降低Gd：Zn比增加。协同溶质效应被认为是至关重要的非基底滑移，溶质偏析，以及形成RE织构成分的激活，并被证明是高度敏感的溶质比。
Synergistic effects of rare earth elements (RE) and Zn have a major impact on the properties of ternary Mg-RE-Zn alloys. This study illuminates their dependence on the solute ratio by comparing texture evolution, solute segregation, and active deformation modes of three Mg-Gd-Zn alloys with a varying Gd:Zn ratio of 2:1, 1:1 and 1:2. A low Gd:Zn ratio led to a texture featuring a pronounced TD-tilted basal pole spread alongside a magnified solute segregation at grain boundaries, indicating a significant impact of solute-boundary interactions on RE-texture formation. Atom probe tomography revealed major alterations of the segregation energy of both Gd and Zn, depending mainly on the solute ratio rather than the absolute solute concentration. Additionally, the alloy with the smallest Gd:Zn ratio, i.e. Gd:Zn = 1:2, showed the highest direction dependent anisotropy of the yield stress under tensile strain, which was attributed to a magnified anisotropy of twinning depending on the Gd:Zn ratio. EBSD assisted slip trace analysis showed that the occurrence of non-basal slip systems could be increased by reducing the Gd:Zn ratio. Synergistic solute effects were found to be crucial for the activation of non-basal slip, solute segregation, as well as the formation of RE-texture components and proven to be highly sensitive to the solute ratio.