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氧化薄膜的局部分解由化物

Eirini Lappa¹, Kyriaki Saltidou¹, Chrysanthi Gkili¹

¹Department of Chemistry, Aristotle University of Thessaloniki, University Campus, Thessaloniki, 54124, Greece.

Chemistry (Weinheim an der Bergstrasse, Germany)

|May 1, 2025

概括

(Nb) 的被动化在化物溶液中分解,导致孔腐蚀,与化物溶液不同. 这种局部腐蚀与氧化膜内的化物吸收和缺陷凝结有关,正如点缺陷模型所解释的那样.

科学领域:

材料科学材料科学材料科学
电化学电化学电化学
腐蚀科学腐蚀科学

背景情况:

(Nb) 形成一个被动的氧化膜,对其耐腐蚀性至关重要.
了解被动薄膜的稳定性对于在侵略性环境中的材料应用至关重要.
局部腐蚀,如坑,仍然是许多金属和合金的一个重大挑战.

研究的目的:

在水性化物介质中研究Nb上的阳极氧化物被动薄膜的稳定性和分解机制.
为了比较Nb在化物与化物溶液中的行为.
用点缺陷模型阐明化物诱导局部腐蚀的物理化学过程.

主要方法:

在水性化物溶液中,潜在动力极化高达12V_SCE.
不同的化物度和潜在的扫描速度.
使用点缺陷模型 (PDM) 进行分析.

主要成果:

被动Nb在化物介质中表现出局部分解 (转移稳定或稳定插孔),取决于度和扫描速率.
在侵略性的化物介质中,Nb保持被动性,对化物表现出不寻常的敏感性.
对于化物诱导的孔腐蚀,确定了临界分解潜力 (E_b).
实验数据与与胺活性和扫描速率相关的E_b的PDM预测一致.

结论:

的被动膜异常容易受到化物诱导的局部分解,与其在化物中的稳定性形成鲜明对比.
分解机制涉及氧化物电解质接口的化物吸收和随后的空隙凝结在Nb氧化物接口.
点缺陷模型有效地解释了观察到的现象,并预测了故障潜力和环境因素之间的关系.

关键词:

化物是一种化物.局部氧化物的分解.的阳极氧化物是的氧化物.点缺陷模型的模型关于空缺的凝结参考文献

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