Abstract The Hall-Petch (H–P) relation for bimodal-grained Mg–Al–Zn alloys consisting of both ultra-fine grains (UFGs)/fine grains (FGs) and coarse grains (CGs) is discussed separately for yield stress and flow stress according to different deformation behaviors of UFGs/FGs and CGs. The yield behavior is controlled by basal dislocation slip of UFGs/FGs and twinning of CGs collectively. Thereafter, non-basal slip is activated in basal-oriented CGs as deformation proceeds. Considering the synergy effect of UFGs/FGs and CGs, we present modified H–P relations for bimodal-grained Mg–3Al–1Zn (AZ31) and Mg–9Al–1Zn (AZ91) alloys containing either few or numerous dispersed particles, respectively, by which the calculated strengths depict experimental values well.

中文翻译：

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探索双峰晶粒Mg-Al-Zn合金的Hall-Petch关系和强化机制

摘要 由超细晶粒 (UFG)/细晶粒 (FG) 和粗晶粒 (CG) 组成的双峰晶粒 Mg-Al-Zn 合金的 Hall-Petch (H-P) 关系分别讨论了屈服应力和根据 UFGs/FGs 和 CGs 不同变形行为的流动应力。屈服行为由 UFGs/FGs 的基底位错滑移和 CGs 的孪晶共同控制。此后，随着变形的进行，非基础滑移在基础取向的 CG 中被激活。考虑到 UFGs/FGs 和 CGs 的协同效应，我们提出了双峰晶粒 Mg-3Al-1Zn (AZ31) 和 Mg-9Al-1Zn (AZ91) 合金的改良 H-P 关系，分别含有少量或大量分散颗粒，计算出的强度很好地描述了实验值。