厚度和环境对复合涂层导电性能的影响

为了给数字化刻铣曲面频率选择表面(FSS)结构的制作和加工提供参考和依据,对比研究了含片状银粉颗粒的聚氨酯基和环氧树脂基2种复合导电涂层的基本性能,并通过环境加速试验,重点研究了温度、湿度以及腐蚀气氛对2种导电涂层的界面强度、微观结构和导电性能的影响.通过电桥法测量涂层表面电阻的变化,并通过扫描电境观察环境试验前后,涂层表面和剖面的微观结构和形貌变化.试验结果表明:聚氨酯基涂层的综合性能优于环氧树脂基涂层;在实验所涉及的参数变化范围内,环境因素对2种涂层与基体的界面结合影响不大,但对其导电性能的影响比较明显.环境因素对导电性能的削弱作用,源于相应过程中导电涂层的微观结构损伤.

Effects of thickness and environmental factors on conductivity of composite coatings

To provide information for the manufacture and application of digital processing frequency selective surface(FSS),the properties of two conductive composite coatings consisting of silver flakes and resin matrix were contrastively investigated.With environmental accelerated test,attention was focused on the effects of environmental factors including temperature,humidity and corrosive atmosphere on their adhesion,microstructure and conductivity.Variation of their surface resistance was measured by bridge method,and their microstructure and pattern change of section and surface were observed before and after environmental test with SEM.The over-all properties of the polyurethane matrix composite coating is better than that of the epoxy resin matrix coating for the two coatings containing silver flakes.The effects of environmental factors on conductivity of the two coatings are obvious,though no appreciable influence on adhesion can be identified in experimental scope and parameter variation range.The negative effect of environmental factors on conductivity is attributed to the micro-damages occurred within the microstructures of the coatings.