基底金属表面处理对有机涂层附着力和电容行为的影响

Effect of Base Metal Surface Treatment on Adhesion and Capacitive Behavior of Organic Coatings

目前传统的涂层附着力测量方法,例如划格法、划叉法、拉开法等多为破坏性试验,已不适用于输电塔防腐涂层的现场质量检测。本工作通过测量不同表面预处理的金属/有机涂层体系的莫特肖特基曲线(Mott-Schottky),对比研究不同体系的半导体性质和电容行为,从而得到涂层附着力和体系电容行为的内在联系。基底金属的表面预处理,如除油磨砂、除锈及磷化硅烷化等对涂层的性能有相当大的影响。实验表明,基体表面污染不仅会促进界面电化学腐蚀,而且削弱有机涂层的防护性能,能够加速涂层失效过程。故基底金属表面处理的好坏对有机涂层防护性能有着至关重要的影响。

At present,the traditional coating adhesion measurement methods,such as the grid method,cross-fork method,and pull-off method,are mostly destructive tests,and are no longer suitable for on-site quality inspection of transmission tower anticorrosive coatings.In this work,Mott-Schottky curves of metal/organic coating systems with different surface pretreatments were measured.So the intrinsic relationship between the coating adhesion and the capacitance behavior of the system is obtained by comparing the semiconductor properties and capacitance behaviors of different systems.The surface treatment of the base metal,such as degreasing,scrubbing,rust removal and phosphation silanization has a considerable impact on the performance of the coating.This work shows that the surface treatment of the substrate has a crucial effect on the protective performance of the organic coating.Experiments have shown that substrate surface pollution not only promotes electrochemical corrosion at the interface,but also weakens the protective properties of the organic coating and can accelerate the coating failure process.Therefore,the quality of the base metal surface treatment has a crucial impact on the protective performance of organic coatings.