Quantitative measurement of corrosion at the nanoscale by in situ spectral modulation interferometry
Quantitative measurement of corrosion at the nanoscale by in situ spectral modulation interferometry
复制标题
原位光谱调制干涉法定量测量纳米尺度腐蚀
DOI：
10.1016/j.matchar.2022.111992
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发表时间：
2022
影响因子：
4.7
通讯作者：
Brand, Alexander S.
中科院分区：
文献类型：
--
作者：
Fanijo, Ebenezer O.;Thomas, Joseph G.;Zhu, Yizheng;Esquivel Guerrero, Javier;Hosking, Niamh C.;Cai, Wenjun;Michel, F. Marc;Brand, Alexander S.
这项研究提出了定量相位显微镜技术、光谱调制干涉测量法 (SMI) 的新颖应用，用于铝合金腐蚀的实时原位纳米尺度表征。 SMI 灵敏度高、图像采集速度快、图像无散斑；因此，可以准确地获得腐蚀过程中表面形貌演变的实时量化，以评估时间和空间相关的腐蚀速率。利用创新的增材制造流体池，在流动溶液条件下原位进行实验。在纳米级 SMI 实验的同时，还通过逐步极化和通过收集的流出溶液等分试样进行溶液化学进行电化学测试，以同时提供确凿的腐蚀速率测量。根据整个腐蚀表面的定量 3D 高度剖面，由快速局部腐蚀引起的凹坑形成是主要的，出现在不同的时间并且在整个表面上不均匀分布。随着实验的进行，计算出的铝随时间变化的溶解速率也随着线性和非线性表面正态分布的组合而变化。在阳极极化的驱动下，[0.40 ± 0.007] μmol m−2s−1 的初始平均线性溶解速率转变为 [1.95 ± 0.035] μmol m−2s−1 的更快速平均速率。三种执行方法的溶解速率遵循相似的趋势，并且可以将纳米级原位 SMI 数据与电化学腐蚀测量和非原位化学溶液分析联系起来。在腐蚀期结束时，通过电化学测量、异位溶液分析和原位 SMI 腐蚀测量分别获得 118 μmol m−2s−1、71 μmol m−2s−1 和 2.45 μmol m−2s−1 的速率。最后，这些实验结果验证了 SMI 对于腐蚀合金表面原位纳米尺度表征的适用性。
This research study presents a novel application of a quantitative phase microscopy technique, spectral modulation interferometry (SMI), forin situnanoscale characterization of corrosion of an aluminum alloy in real time. SMI offers high sensitivity, rapid image acquisition, and speckle-free images; thus, real-time quantification of surface topography evolution during corrosion can be obtained accurately to evaluate the temporally- and spatially-dependent corrosion rates. With an innovative additive-manufactured fluid cell, experiments were performedin situunder flowing solution conditions. Electrochemical tests via stepwise polarization and solution chemistry through collected aliquots of outflow solution were also performed alongside the nanoscale SMI experiment to simultaneously provide a corroborating corrosion rate measurement. Based on the quantitative 3D height profiles across the corroded surface, pit formation resulting from rapid local corrosion was predominant, appearing at different times and are heterogeneously distributed across the surface. The computed time-dependent dissolution rates of aluminum also varied as the experiment proceeded, with the combination of linear and nonlinear surface normal distributions. An initial mean linear dissolution rate of [0.40 ± 0.007] μmol m−2s−1transitioned to a more rapid mean rate of [1.95 ± 0.035] μmol m−2s−1, driven by the anodic polarization. Dissolution rates from the three performed methods follow similar trends and there is the visibility of linking the nanoscalein situSMI data to the electrochemical corrosion measurements andex situchemical solution analysis. At the end of the corrosion period, rates of 118 μmol m−2s−1, 71 μmol m−2s−1, and 2.45 μmol m−2s−1were obtained from electrochemical measurements,ex situsolution analyses, andin situSMI corrosion measurement, respectively. Finally, these experimental results validate the applicability of SMI forin situnanoscale characterization of a corroding alloy surface.