DOI:10.11973/fsyfh-202212004片层蒙脱土对溶胶-凝胶涂层防腐蚀性能的影响郭华龙,刘煊煊,高燕,张俊喜(上海电力大学,上海200090)摘要:为改善无机涂层脆性大、成膜性差的问题,以正硅酸四乙酯为原料,片层蒙脱土为填料,采用溶胶凝胶法在AA2024铝合金表面制备了蒙脱土溶胶-凝胶涂层。利用扫描电镜(SEM)、能谱仪(EDS)和傅里叶红外光谱仪((FT-IR))分析了涂层的微观形貌和聚合原理。通过动电位极化和电化学阻抗谱测试,研究了所制备的涂层在3.5%NaCl溶液中的电化学行为,并与纯硅溶胶涂层和基体进行比较。结果表明:制备的蒙脱土纳米片,其厚度最小约为10nm,直径最小约为500nm;蒙脱土在涂层中分布较为均匀,在溶胶聚合过程中,蒙脱土在溶胶中引导溶胶粒子有序聚合,提高了涂层的致密度,减少了固化时涂层产生的缺陷;蒙脱土溶胶-凝胶涂层试样的腐蚀电流密度(1.04×10-8A·cm-2)比纯硅溶胶涂层试样(1.22×10-7A·cm-2)低1个数量级,蒙脱土溶胶-凝胶涂层具有较高的涂层阻抗,且蒙脱土溶胶-凝胶涂层的Rct始终远高于纯硅溶胶涂层,表明蒙脱土溶胶-凝胶涂层具有更持久的防护效果。关键词:无机涂层;蒙脱土;腐蚀防护;AA2024铝合金中图分类号:TG174文献标志码:A文章编号:1005-748X(2022)12-0021-09EffectofLamellarMontmorilloniteonCorrosionProtectionofSol-GelCoatingGUOHualong,LIUXuanxuan,GAOYan,ZHANGJunxi(ShanghaiUniversityofElectricPower,Shanghai20090,China)Abstract:Inordertoimprovethebrittlenessandpoorfilm-formingpropertyoftheinorganiccoating,amontmorillonitesol-gelcoatingwaspreparedonthesurfaceofAA2024aluminumalloybysol-gelmethodwithtetraethylorthosilicateasrawmaterialandlamellarmontmorilloniteasfiller.Scanningelectronmicroscopy(SEM),energydispersivespectroscopy(EDS)andFouriertransforminfraredspectroscopy(FT-IR)wereusedtoanalyzethemicro-morphologyandpolymerizationprincipleofthecoating.Theelectrochemicalbehaviorofthecoatingin3.5%NaClsolutionwasstudiedbypotentiodynamicpolarizationandelectrochemicalimpedancespectroscopytest,andcomparedwithpuresilicasolcoatingandsubstrate.Theresultsshowedthatthelowestthicknessofmontmorillonitenanosheetswasabout10nmandthediameterwasabout500nm.Montmorillonitewasevenlydistributedinthecoating.Intheprocessofsolpolymerization,montmorilloniteguidedtheorderedp...
