湿热环境中阳极氧化铝合金表面RFH环氧涂层的防护性能及其改善

为了确定湿热环境对RFH环氧涂层的影响,通过涂层外观、变形量、表面形貌及红外光谱分析,发现RFH环氧涂层在湿热作用下,涂层外观及形貌发生了明显变化,涂层表面由亚光转变为无光,并产生严重的翘曲鼓包变形和微裂纹;红外光谱分析确定涂层表面环氧树脂特征吸收峰减弱。研究结果表明:在湿热条件下涂层表面发生了一定程度的老化,塑性下降,同时在内应力作用下,附着力下降,从而出现了较大变形鼓包以及失光、裂纹。通过表面配套防护涂层改进及验证,确定采用有机硅涂层和底涂的表面防护体系,可以有效改善涂层耐湿热性。

Influence of Damp Heat Test on Protective Performance of RFH Epoxy Coating and Its Improvement

It is found that the RFH epoxy coating changed obviously in terms of film appearance and surface morphology by analysis of film appearance, distortion measure and surface topography. Specifically, the coating turns its semi-gloss into matte appearance and serious curling, blister and micro-crack occur. The FT-IR spectroscopy shows that the peak of epoxy resin is weakened. The results show that the plasticity of the coating surface decreases and its adhesion also decreases due to inner stress which results in film defects including blister, flatting and crack. By means of modification of supporting protective coating, it is indicated that the silicone coating and primer are effective to improve the humid heat resistance of the epoxy coating.