An Investigation of the Fundamental Aspects of Underfilm Corrosion

膜下腐蚀基本方面的研究

• 批准号: 9708148
• 负责人: Ronald Latanision
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-15 至 2001-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9708148&HistoricalAwards=false
• 关键词: Investigation; Fundamental; Aspects; Underfilm; Corrosion

9708148 Latanision Past effort on understanding the structure and dynamics of interfacial processes in underfilm corrosion has resulted in non-destructive electrochemical techniques to monitor underfilm corrosion. Most of the data reported in the current literature have been generated by the technique of Electrochemical Impedance Spectroscopy (EIS). These data suggest that: (1) corrosion initiates well before it can be detected optically; (2) delamination results from either a loss of adhesion or corrosion at the polymer-metal interface; and (3) delamination and corrosion rate can only be estimated by EIS. In order to achieve a better understanding of underfilm degradation, it is imperative that the correlation between electrochemistry, loss of metal, and delamination rate is fully understood. While a correlation between electrochemistry and corrosion rate is well established for non-coated samples, no accurate measurement of mass loss beneath a polymer coating has been achieved. This FRG (Focussed Research Group) project circumvents the problems associated with determining the change in mass of a coated substrate by following the change in the magnetic saturation of a polymer-coated ferromagnetic sample. Mass loss is assessed with a vibrating sample magnetometer (VSM), which provides an unambiguous method for determining the corrosion rate of a coated sample. In addition, the sample is monitored visually and with EIS. When correlated to visual and electrochemical data, these results should provide significant insight into the evaluation of underfilm corrosion and assessment of coating performance. The current research should also be able to distinguish between delamination resulting from loss of adhesion or from corrosion. During an experiment, if no metal loss is recorded on the VSM but delamination is visually and electrochemically detected, it can not be associated with corrosion. In this FRG project emphasis is also placed on the development of an in-situ/real-time electrochemical technique (Fast Transient Technique, FTT) to monitor solute uptake and the initial stage of coating degradation. The grant is co-funded by the MPS Office of Multidisciplinary Activities and the Division of Materials Research. %%% This project is expected to lead to an improved understanding of both the reliability of protective organic coatings and the use of electrochemical techniques (EIS and FTT), thereby providing a basis for the selection of the most suitable commercially available protective coatings. ***

9708148拉丁裔 过去对膜下腐蚀界面过程的结构和动力学的理解导致了非破坏性电化学技术来监测膜下腐蚀。 目前文献中报道的大部分数据都是由电化学阻抗谱（EIS）技术产生的。 这些数据表明：（1）腐蚀在光学检测之前就开始了;（2）分层是由于聚合物-金属界面处的粘附力丧失或腐蚀造成的;（3）分层和腐蚀速率只能通过EIS估计。 为了更好地理解底膜降解，必须充分理解电化学、金属损失和分层速率之间的相关性。 虽然电化学和腐蚀速率之间的相关性是很好地建立了非涂层样品，没有准确的测量聚合物涂层下的质量损失已经实现。 这个FRG（Focussed Research Group）项目通过跟踪聚合物涂层铁磁样品的磁饱和度变化，规避了与确定涂层基底质量变化相关的问题。 质量损失评估与振动样品磁强计（VSM），它提供了一个明确的方法来确定涂层样品的腐蚀速率。 此外，目视监测样品并使用EIS。 当与视觉和电化学数据相关时，这些结果应该为膜下腐蚀的评估和涂层性能的评估提供重要的见解。 目前的研究也应该能够区分脱层造成的损失的粘附力或腐蚀。 在实验过程中，如果VSM上没有记录到金属损失，但通过目视和电化学检测到分层，则不能将其与腐蚀联系起来。 在这个联邦德国项目的重点也放在一个原位/实时电化学技术（快速瞬态技术，FTT）的发展，以监测溶质的吸收和涂层降解的初始阶段。该补助金由MPS多学科活动办公室和材料研究部共同资助。 该项目有望提高对保护性有机涂层的可靠性和电化学技术（EIS和FTT）的使用的理解，从而为选择最合适的商用保护性涂层提供依据。 ***