Bradley R S, Liu Y, Burnett T L, Zhou X, Lyon S B, Withers P J, Gholinia A, Hashimoto T, Graham D, Gibbon S R, Hornberger B
Henry Moseley X-ray Imaging Facility, The University of Manchester, Manchester, M13 9PL, U.K.
School of Materials, The University of Manchester, Manchester, M13 9PL, U.K.
J Microsc. 2017 Jul;267(1):98-106. doi: 10.1111/jmi.12551. Epub 2017 Apr 17.
An experimental protocol (workflow) has been developed for time-lapse x-ray nanotomography (nano-CT) imaging of environmentally driven morphological changes to materials. Two case studies are presented. First, the leaching of nanoparticle corrosion inhibitor pigment from a polymer coating was followed over 14 days, while in the second case the corrosion damage to an AA2099 aluminium alloy was imaged over 12 hours. The protocol includes several novel aspects relevant to nano-CT with the use of a combination of x-ray absorption and phase contrast data to provide enhanced morphological and composition information, and hence reveal the best information to provide new insights into the changes of different phases over time. For the pigmented polymer coating containing nominally strontium aluminium polyphosphate, the strontium-rich components within the materials are observed to leach extensively whereas the aluminium-rich components are more resistant to dissolution. In the case of AA2099 it is found that the initial grain boundary corrosion is driven by the presence of copper-rich phases and is then followed by the corrosion of grains of specific orientation.
已开发出一种实验方案（工作流程），用于对环境驱动的材料形态变化进行延时X射线纳米断层扫描（纳米CT）成像。本文展示了两个案例研究。第一个案例中，对聚合物涂层中纳米颗粒缓蚀剂颜料的浸出过程进行了为期14天的跟踪，而在第二个案例中，对AA2099铝合金的腐蚀损伤进行了为期12小时的成像。该方案包括几个与纳米CT相关的新颖方面，即使用X射线吸收和相衬数据的组合来提供增强的形态和成分信息，从而揭示最佳信息，以便深入了解不同相随时间的变化。对于名义上含有多磷酸锶铝的着色聚合物涂层，观察到材料中富含锶的成分大量浸出，而富含铝的成分更耐溶解。在AA2099的案例中，发现初始晶界腐蚀是由富铜相的存在驱动的，随后是特定取向晶粒的腐蚀。
