Atmospheric Corrosion of Aluminum in the Presence of Ammonium Sulfate Particles
Atmospheric Corrosion of Aluminum in the Presence of Ammonium Sulfate Particles
复制标题
DOI：
10.1149/1.1836615
复制
发表时间：
1996-05
影响因子：
3.9
通讯作者：
R. Lobnig;D. Siconolfi;J. Maisano;G. Grundmeier;H. Streckel;R. P. Frankenthal;M. Stratmann;J. Sincla
中科院分区：
文献类型：
--
作者：
R. Lobnig;D. Siconolfi;J. Maisano;G. Grundmeier;H. Streckel;R. P. Frankenthal;M. Stratmann;J. Sincla
在300 K和373K的空气-水蒸气混合物中，研究了锌在(NH{sub4}){sub2}SO{sub4}粒子存在下的大气腐蚀。腐蚀产物的形成通过几种原位技术进行跟踪，包括傅里叶变换红外光谱、X射线衍射、pH测量和扫描开尔文探针测量。与以前对铜和铝的研究不同，锌在临界相对湿度(CRH)(NH{sub4}){sub2}so{sub4}下与粒子发生反应。在300K时，反应发生在相对湿度(RH)为65%的条件下，而不是在60%/RH条件下。这归因于表面存在碱性碳酸锌，它能在如此低的相对湿度下吸收足够的水，使电化学反应成为可能。在(NH{sub4}){sub2}SO{sub4}的CRH以上，锌与(NH{sub4}){sub2}SO{sub4}反应生成混合的硫酸锌铵，然后与碱式硫酸锌反应，在373K时再加锌矿(氧化锌)。在(NH{sub4}){sub2}SO{sub4}的CRH以上，在颗粒周围形成液滴后，腐蚀电位直接下降，锌变得活跃。提出了腐蚀机理来解释这些观察结果。
The atmospheric corrosion of zinc in the presence of (NH{sub 4}){sub 2}SO{sub 4} particles has been investigated at 300 and 373 K in air-water vapor mixtures. The development of corrosion products was followed by several in situ techniques, including Fourier transform infrared-spectroscopy, X-ray diffraction, pH measurements, and scanning Kelvin probe measurements. Unlike earlier work on copper and aluminum, zinc reacts with the particles below the critical relative humidity (CRH) of (NH{sub 4}){sub 2}SO{sub 4}. At 300 K reaction was observed at 65% relative humidity (RH), but not at 60% /RH. This is attributed to the presence of basic zinc carbonate on the surface, which absorbs sufficient water at this low RH to make electrochemical reactions possible. At and above the CRH of (NH{sub 4}){sub 2}SO{sub 4}, zinc reacts with (NH{sub 4}){sub 2}SO{sub 4} forming mixed ammonium zinc sulfate and later on basic zinc sulfate, and at 373 K additionally zincite (ZnO). Above the CRH of (NH{sub 4}){sub 2}SO{sub 4}, the corrosion potential decreases directly after formation of droplets surrounding the particles and zinc becomes active. Corrosion mechanisms are proposed to explain the observations.