Understanding the mechanistic relationship between the environment, microstructure, and local kinetics of atmospheric corrosion damage remains a central challenge. To address this challenge, this study used laboratory-based X-ray tomography to directly observe attack in-operando over an extended period, enabling insights into the evolving growth kinetics and morphology of individual pits over months of exposure. Damage progression associated with nine pits in a 99.9% pure aluminum wire exposed to chloride salts in humid air was characterized. Most pits grew at a nominally linear rate up until pit death, which occurred within 12–24 h of nucleation. Exceptions to this were observed, with three pits exhibiting bimodal growth kinetics and growing for 40 or more hours. This was explained by secondary droplets that formed near the pits, increasing the cathode area. A corrosion-driven drying mechanism likely contributed to pit death in both cases. Pits first grew into the material followed by lateral expansion.

了解环境，微观结构和大气腐蚀破坏的局部动力学之间的机械关系仍然是一个主要挑战。为了应对这一挑战，这项研究使用了基于实验室的X射线断层扫描技术，可以在较长时期内直接观察操作中的攻击，从而可以洞悉暴露几个月后各个凹坑的不断发展的生长动力学和形态。表征了与在潮湿空气中暴露于氯盐的99.9％纯铝线中的9个凹坑相关的损伤进程。大多数凹坑以名义上的线性速率生长，直到凹坑死亡（发生在成核的12-24小时内）。观察到例外，三个凹坑表现出双峰生长动力学并生长了40个小时或更长时间。这可以通过凹坑附近形成的次级液滴来解释，增加阴极面积。在两种情况下，腐蚀驱动的干燥机制都可能导致凹坑死亡。坑首先长成材料，然后横向膨胀。