Abstract In the present work, the elastic behavior of a metastable β-Ti alloy, Timetal-18, is studied in the β-quenched condition using in-situ far-field (ff) and near-field (nf) high energy synchrotron X-ray diffraction microscopy (HEDM) techniques and full-field crystal elasticity simulation. HEDM enables assessment of the 3D microstructure as well as the complete (6 components) elastic strain tensor and crystallographic orientation of each grain in the gauge volume of a polycrystalline aggregate. Using this elastic strain and orientation data from ~100 grains, a straightforward strategy to obtain the single crystal elastic constants (SEC) is demonstrated. The elastic moduli thus obtained are (in GPa): C11 = 118 ± 5, C12 = 79 ± 3, C44 = 39 ± 4, with a Zener anisotropy ratio (A) of 2.0 ± 0.4. The nf-HEDM 3D microstructure was used to instantiate a virtual microstructure, as input into the parallelized code, Micromechanical Analysis of Stress-strain Inhomogeneities with fast Fourier transform (MASSIF), in order to simulate the grain level constitutive response. The predicted evolutions of the elastic strain tensor components are shown to be in good agreement with the measured values. However, grain-by-grain comparisons emphasize the strong effect of elastic anisotropy, suggesting it may be even higher than A = 2. The accuracy of the approach and implications for modeling the grain-level constitutive response in the plastic regime are discussed.

中文翻译：

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亚稳态β-钛合金弹性响应的原位高能X射线衍射研究

摘要 在目前的工作中，使用原位远场 (ff) 和近场 (nf) 高能同步加速器 X 在 β 淬火条件下研究了亚稳态 β-Ti 合金 Timetal-18 的弹性行为。射线衍射显微镜 (HEDM) 技术和全场晶体弹性模拟。HEDM 能够评估 3D 微观结构以及完整的（6 个分量）弹性应变张量和多晶骨料计量体积中每个晶粒的晶体取向。使用来自~100 个晶粒的弹性应变和取向数据，展示了获得单晶弹性常数 (SEC) 的直接策略。由此获得的弹性模量（以 GPa 为单位）：C11 = 118 ± 5，C12 = 79 ± 3，C44 = 39 ± 4，齐纳各向异性比 (A) 为 2.0 ± 0.4。nf-HEDM 3D 微结构用于实例化虚拟微结构，作为并行代码“快速傅里叶变换应力-应变不均匀性微机械分析 (MASSIF)”的输入，以模拟晶粒级本构响应。弹性应变张量分量的预测演变与测量值非常吻合。然而，逐粒比较强调了弹性各向异性的强影响，表明它甚至可能高于 A = 2。讨论了该方法的准确性和对塑性状态下的晶粒级本构响应建模的影响。以模拟晶粒级本构响应。弹性应变张量分量的预测演变与测量值非常吻合。然而，逐粒比较强调了弹性各向异性的强影响，表明它甚至可能高于 A = 2。讨论了该方法的准确性和对塑性状态下的晶粒级本构响应建模的影响。以模拟晶粒级本构响应。弹性应变张量分量的预测演变与测量值非常吻合。然而，逐粒比较强调了弹性各向异性的强影响，表明它甚至可能高于 A = 2。讨论了该方法的准确性和对塑性状态下的晶粒级本构响应建模的影响。