Shock recovery experiments are essential for interrogating the structure-property relationships in condensed matter under extreme dynamic environments such as elevated stresses, temperatures, and strain rates. Although the shock compression science community has employed recovery experiments to develop a significant body of knowledge on the structure-property relationships in shock compressed solids; nevertheless, shock recovery experiments are end state experiments. The microstructure evolution and deformation mechanisms active during shock compression and stress release are not captured in real-time and therefore, are not well understood at the fundamental level. This suggests that a knowledge gap exists between the ambient and end states. Hence, this knowledge gap poses some serious challenges on the interpretation of the microstructural data acquired from shock recovery experiments. Therefore, to elucidate the complex behavior and self-inconsistent results derived from shock recovery experiments; fine grained AMX602 magnesium alloy was shock compressed to stable Hugoniot stresses of approximately 2.0 GPa and 7.0 GPa respectively, along the plate normal and extrusion directions, then released back to ambient conditions. Using time-resolved in-situ synchrotron X-ray diffraction shock experiments, we report the real-time observation of twinning-detwinning in this fine grained AMX602 magnesium alloy. Texture evolution via in-situ X-ray diffraction show significant twinning during shock compression and detwinning during stress release. These findings were ascertained through the intensity interchange between the parent and twin reflection pair (0002)-basal and (10 -10)-prismatic, which occur during {10-12}10-1-1 extension twinning in materials with hexagonal closed pack lattice structure. These results not only provide a strong insight on the complex twinning-detwinning behavior of this textured fine-grained AMX602 magnesium alloy, but they also helped in bridging the existing knowledge gap in shock recovery experiments.

中文翻译：

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通过时间分辨定点电子回旋加速器XRD实验实时观察休克压缩镁中的孪生孪晶

冲击恢复实验对于在极端动态环境（例如应力，温度和应变率升高）下询问凝结物中的结构特性关系至关重要。尽管冲击压缩科学界已经采用恢复实验来开发大量有关冲击压缩固体中结构-性质关系的知识；但是，但是，冲击恢复实验是最终状态实验。在冲击压缩和应力释放过程中活跃的微观结构演化和变形机制无法实时捕获，因此在基本层面上还没有得到很好的理解。这表明在环境状态和最终状态之间存在知识鸿沟。因此，这种知识上的差距对从冲击恢复实验获得的微观结构数据的解释提出了一些严峻的挑战。因此，要阐明冲击恢复实验的复杂行为和自相矛盾的结果；将细晶粒的AMX602镁合金沿板法线方向和挤压方向进行冲击压缩，分别达到约2.0 GPa和7.0 GPa的稳定Hugoniot应力，然后释放回环境条件。使用时间分辨的原位同步加速器X射线衍射冲击实验，我们报告了这种细晶粒AMX602镁合金中孪晶-孪晶的实时观察。通过原位X射线衍射进行的织构演变表明，在冲击压缩过程中，孪晶显着孪生，在应力释放过程中，孪晶解缠。这些发现是通过在具有六边形密堆积材料的{10-12} 10-1-1延伸孪晶过程中发生的母体和孪生反射对（0002）-基础和（10 -10）-棱晶之间的强度互换来确定的。晶格结构。这些结果不仅为这种纹理细化的AMX602镁合金的复杂孪生-不孪生行为提供了深刻的见解，而且还有助于弥合冲击恢复实验中的现有知识差距。