机构地区: 哈尔滨工程大学材料科学与化学工程学院
出 处: 《金属热处理》 2007年第9期83-86,共4页
摘 要: 分别在刷涂于铁基体、A l电弧喷涂层和Zn-A l-Mg-RE电弧喷涂层表面的有机涂层中制备了大小不同的人工缺陷,观察了各体系进行电化学交流阻抗(EIS)测试后有机涂层的失效形貌及缺陷处腐蚀产物的微观结构,并分析了各体系的失效机制。结果表明,对于在铁基体和A l电弧喷涂层表面刷涂有机涂层体系,缺陷尺寸越小,有机涂层失效越严重,主要是因为缺陷大小影响腐蚀产物向腐蚀介质中的扩散造成的;对于在Zn-A l-Mg-RE电弧喷涂层表面刷涂有机涂层的体系,缺陷尺寸大小对有机涂层失效形貌的影响不大,主要是因为在人工孔隙中生成了微观结构致密的腐蚀产物造成的。 Artificial defects with different dimension were prepared in organic coatings, which were applied on steel, A1 arc spraying coating and Zn-Al-Mg-RE arc spraying coating, respectively. Failure patterns of the organic coatings and microstructure of corrosion products around defects were observed after EIS measurements, and the failure mechanism of different systems were analyzed. The results show that the smaller the defect dimension, the more serious failure the organic coatings applied on steel and A1 arc spraying coating systems, which is ascribed to that the defect dimension influences the diffusion of corrosion products to corrosive medium. The defect dimension has negligible influence on the failure patterns of the organic coatings applied on Zn-Al-Mg-RE arc spraying coating system, due to the formation compact corrosion products in the artificial defects.