Dispersions of nanoscale precipitates in metallic alloys have been known to play a key role in strengthening, by increasing their strain hardenability and providing resistance to deformation. Although these phenomena have been extensively investigated in the last century, the traditional approaches employed in the past have not rendered an authoritative microstructural understanding in such materials. The effect of the precipitates' inherent complex morphology and their 3D spatial distribution on evolution and deformation behavior have often been precluded. This study reports, for the first time, implementation of synchrotron‐based hard X‐ray nanotomography in Al–Cu alloys to measure kinetics of different nanoscale phases in 3D, and reveals insights behind some of the observed novel phase transformation reactions. The experimental results of the present study reconcile with coarsening models from the Lifshitz–Slyozov–Wagner theory to an unprecedented extent, thereby establishing a new paradigm for thermodynamic analysis of precipitate assemblies. Finally, this study sheds light on the possibilities for establishing new theories for dislocation–particle interactions, based on the limitations of using the Orowan equation in estimating precipitation strengthening.

中文翻译：

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使用4D纳米尺度表征探索铝合金中的新型微结构演化机制

已知金属合金中纳米级沉淀物的分散体通过增强应变硬化性并提供抗变形性，在增强合金中起关键作用。尽管在上个世纪已经对这些现象进行了广泛的研究，但过去采用的传统方法并未在此类材料中获得权威的微观结构理解。通常排除了沉淀物固有的复杂形态及其3D空间分布对演化和变形行为的影响。这项研究首次报道了在Al-Cu合金中实施基于同步加速器的硬X射线纳米断层照相术，以测量3D中不同纳米级相的动力学，并揭示了一些已观察到的新型相变反应背后的见解。本研究的实验结果与Lifshitz–Slyozov–Wagner理论的粗化模型相一致，达到了前所未有的程度，从而为沉淀物组合物的热力学分析建立了新的范例。最后，基于使用Orowan方程估算降水强化的局限性，这项研究为建立位错-粒子相互作用的新理论提供了可能性。