Solidification processing offers the first opportunity to control microstructure, properties, and performance in metallic alloy components. Until recently, microstructural evaluations were limited to post-solidification characterization by destructive methods. We review the development of time-resolved, in situ imaging techniques capable of capturing solid–liquid interfacial evolution in metallic alloys with high spatial and temporal resolution under diverse solidification conditions relevant for applications ranging from conventional directional solidification, crystal growth, and casting, to welding and additive manufacturing. These experiments enable direct visualization of transient behaviors that would otherwise remain unknown, uniquely providing insights into the physics that impact microstructure and defect development, and strategies for microstructural control and defect mitigation. Understanding microstructural evolution and the characteristics that form under various solidification conditions is essential for the development of multiscale, experimentally informed predictive modeling. This is highlighted by solidification simulations that utilize in situ measurements of solidification dynamics from state-of-the-art experimental techniques.

凝固处理为控制金属合金部件的微观结构，性能和性能提供了第一个机会。直到最近，微结构评估还仅限于通过破坏性方法进行凝固后表征。我们在原地回顾时间分辨的发展能够在各种凝固条件下以高时空分辨率捕获金属合金中固液界面演化的成像技术，涉及从常规定向凝固，晶体生长和铸造到焊接和增材制造的各种应用。这些实验能够直接可视化瞬态行为，否则这些瞬态行为将仍然是未知的，从而独特地提供了影响微观结构和缺陷发展的物理学见解，以及微观结构控制和缺陷缓解的策略。了解微观结构的演变以及在各种凝固条件下形成的特征对于开发多尺度，以实验为依据的预测模型至关重要。使用最新的实验技术进行凝固动力学的现场测量。