Effect of microstructure on passive film formation and breakdown of Al–Ta alloys
Effect of microstructure on passive film formation and breakdown of Al–Ta alloys
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微观结构对 Al-Ta 合金钝化膜形成和破坏的影响
DOI：
10.1039/fd9929400127
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
P. Moran
中科院分区：
文献类型：
--
作者：
J. Kruger;R. Lillard;C. C. Streinz;P. Moran
采用动态成像微椭圆偏振法（DIM）和局部电化学阻抗谱（LEIS）两种原位测试技术，研究了Al-Ta合金表面微观结构对钝化膜形成和击穿的影响。DIM以大约1000的空间分辨率获取椭圆偏振数据（表面上薄膜的厚度和光学常数）。20 µm使用辐射全场成像方法。LEIS是一种电化学阻抗技术，其产生局部a.c.通过测量交流阻抗数据溶液电流密度非常接近电极表面的微观结构特征。DIM技术用于观察在（a）Al 3 Ta沉淀物、（B）与沉淀物相邻的脱合金区和（c）存在于Al-Ta合金中的固溶体相处的钝化膜形成。DIM技术观察到不同的膜厚度和光学常数的膜上形成的这些阶段在电位在被动区。的LEIS技术被用来研究沉淀物和周围的区域在钝化膜击穿发生的条件下。利用这些技术，深入了解了钝化膜的形成和控制局部腐蚀的击穿过程
Two in situ techniques dynamic imaging microellipsometry (DIM) and local electrochemical impedance spectroscopy (LEIS), have been applied to a study of the effect of microstructure on passive film formation and breakdown on Al–Ta alloys. DIM acquires ellipsometric data (thickness and optical constants of the films on surfaces) at a spatial resolution of ca. 20 µm using a radiometric full-field imaging approach. LEIS is an electrochemical impedance technique that generates local a.c. impedance data by measuring a.c. solution current densities very near the microstructural features of an electrode surface. The DIM technique was used to look at passive film formation at (a) the Al3Ta precipitate, (b) the dealloyed zone adjacent to the precipitate and (c) the solid solution phase that is present in Al-Ta alloys. The DIM technique observed different film thickness and optical constants for the films that form on these phases at potentials in the passive regions. The LEIS technique was used to study the precipitate and the region surrounding it under conditions where passive film breakdown occurs. Using these techniques, insight was obtained into the passive film formation and breakdown processes that control localized corrosion