Abstract A unique approach to correlating an evolving 3D microstructure in an Al-Cu alloy and its micro-scale mechanical properties has been introduced. Using these nanoscale three-dimensional microstructures derived from Transmission X-ray Microscopy (TXM), individual contributions from different strengthening mechanisms were quantified. The spatial distribution and morphology of the individual θ′ and θ phases were seen to play an important role in influencing dislocation storage. Uniaxial micro-compression experiments were used to quantify the stress-strain response of the alloy at different aging times. Transmission electron microscopy (TEM) aided in discerning dislocation activity at these precipitates. A model is proposed to accurately predict the variation in yield stress by using appropriate morphological parameters from the 3D microstructure and its validity has been corroborated using experimental measurements. Distributions of 2D and 3D inter-precipitate spacing were seen to provide crucial insights on influencing deformation in such precipitation-strengthened alloys. Finally, the transition in deformation behavior and origin of numerous strain bursts were investigated using in situ micropillar compression testing.

中文翻译：

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Al-Cu 合金的显微组织演变和变形行为：透射 X 射线显微镜 (TXM) 和微柱压缩研究

摘要 本文介绍了一种将 Al-Cu 合金中不断演变的 3D 微观结构与其微观机械性能相关联的独特方法。使用这些源自透射 X 射线显微镜 (TXM) 的纳米级三维微结构，量化了来自不同强化机制的个体贡献。单个 θ' 和 θ 相的空间分布和形态被认为在影响位错存储方面起着重要作用。单轴微压缩实验用于量化合金在不同时效时间的应力应变响应。透射电子显微镜 (TEM) 有助于辨别这些沉淀物的位错活动。提出了一种模型，通过使用来自 3D 微观结构的适当形态参数来准确预测屈服应力的变化，并且其有效性已通过实验测量得到证实。2D 和 3D 间析出间距的分布被认为为影响这种析出强化合金的变形提供了重要的见解。最后，使用原位微柱压缩测试研究了变形行为的转变和大量应变爆发的起源。