Abstract The constitutive behavior of a hexagonal close-packed (HCP) polycrystalline ZEK100 magnesium alloy was investigated using combined high energy X-ray diffraction (HEXRD) from a synchrotron source and crystal plasticity modeling approach. The in-situ tensile test data coupled with the HEXRD enabled the tracking of the lattice strain evolution during deformation. The microscopic behavior represented by lattice strain and the macroscopic behavior represented by stress-strain curves were then used together as objective function to estimate the critical resolved shear stress (CRSS) and hardening parameters of available slip and deformation twin systems in the ZEK100 alloy. An enhanced predominant twinning reorientation (ePTR) scheme was proposed in the current work, and the ePTR parameters were determined for the first time by the use of basal plane peak intensity along loading direction measured from HEXRD. Two crystal plasticity models, the computationally efficient elastic-plastic self-consistent (EPSC) and crystal plasticity finite element (CPFE) models, were developed incorporating the deformation twinning for the HCP-structured metals. The determined constitutive parameters were further validated by comparing the predicted deformation texture with the measured one. The work provides a useful and computationally-efficient modeling scheme to understand the slip/twin induced deformation behaviors of the ZEK100 alloy in micro- and macro-scales.

中文翻译：

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基于机理的 ZEK100 镁合金晶体塑性本构建模和原位 HEXRD 实验

摘要 使用来自同步加速器源和晶体塑性建模方法的组合高能 X 射线衍射 (HEXRD) 研究了六角密堆积 (HCP) 多晶 ZEK100 镁合金的本构行为。原位拉伸试验数据与 HEXRD 相结合，可以跟踪变形过程中的晶格应变演变。然后将晶格应变表示的微观行为和应力-应变曲线表示的宏观行为一起用作目标函数，以估计 ZEK100 合金中可用滑移和变形孪生系统的临界解析剪切应力 (CRSS) 和硬化参数。在当前的工作中提出了一种增强的主导孪生重定向（ePTR）方案，ePTR 参数首次通过使用沿加载方向从 HEXRD 测量的基面峰强度确定。开发了两种晶体塑性模型，即计算效率高的弹塑性自洽 (EPSC) 和晶体塑性有限元 (CPFE) 模型，结合了 HCP 结构金属的变形孪生。通过将预测的变形纹理与测量的纹理进行比较，进一步验证了确定的本构参数。这项工作提供了一种有用且计算效率高的建模方案，以了解 ZEK100 合金在微观和宏观尺度上的滑移/孪生诱导变形行为。计算高效的弹塑性自洽 (EPSC) 和晶体塑性有限元 (CPFE) 模型是结合 HCP 结构金属的变形孪生开发的。通过将预测的变形纹理与测量的纹理进行比较，进一步验证了确定的本构参数。这项工作提供了一种有用且计算效率高的建模方案，以了解 ZEK100 合金在微观和宏观尺度上的滑移/孪生诱导变形行为。计算高效的弹塑性自洽 (EPSC) 和晶体塑性有限元 (CPFE) 模型是结合 HCP 结构金属的变形孪生开发的。通过将预测的变形纹理与测量的纹理进行比较，进一步验证了确定的本构参数。这项工作提供了一种有用且计算效率高的建模方案，以了解 ZEK100 合金在微观和宏观尺度上的滑移/孪生诱导变形行为。