【摘要】 选用飞机上广泛使用的氟聚氨酯蒙皮涂层,采用电化学交流阻抗技术(EIS)对其在加速老化试验过程中的阻抗变化进行了原位测试,分析了其腐蚀失效的特征。研究表明,氟聚氨酯涂层的缺陷较少,涂层可以很好地将腐蚀性介质阻挡在外,保护金属基体免受腐蚀破坏,此时涂层相当于一个纯电容。随着加速老化试验的进行,氟聚氨酯蒙皮涂层的失光率和色差变化较小,引起涂层体系失效的主要原因还是发生在涂层/金属界面的电化学反应。加速老化试验进行1680h后,氟聚氨酯蒙皮涂层的电化学交流阻抗谱上仍然显示的是纯电容性质,而且由等效电路计算出此时的涂层电容仍然很小,说明此时氟聚氨酯磁漆仍起着很好的保护基体的作用。与只喷涂锌黄丙烯酸聚氨酯底漆而没有氟聚氨酯面层的试样的加速老化试验结果比较可知,氟聚氨酯面漆可以有效提高底涂层抗老化和失效性能。更多还原

【Abstract】 The electrochemical impedance varieties of containing fluorine polyurethane topcoat in aircraft during accelerated aging test were studied by means of electrochemical impedance spectroscopy(EIS),and the corrosive failure behavior of the coatings was also investigated.It has been found that the topcoat acts as a pure capacitance before the aging test and can insolate the corrosive media.With the aging time,there is little change of brightness loss and color difference.After 1680h of exposure to the test,the EIS of the topcoat also shows a pure capacitance,and the capacitance calculated according to the equivalent circuit is also very small.It indicates that the topcoat can provide significant protection to aluminum alloy substrate.Comparing with the result of zinc yellow polypropylene primer coated aluminum alloy without the topcoat,the topcoat can improve the anti-aging property greatly.更多还原