建筑铝材表面复合阳极氧化膜的制备及其性能研究

Study on preparation and properties of composite anodized film on surface of construction aluminum

为进一步提高建筑铝材表面性能,以满足苛刻的应用要求,采用添加PTFE(Polytetrafluoroethylene,简写为PTFE)乳液的电解液在铝材表面制备复合阳极氧化膜,研究了PTFE乳液体积分数对复合阳极氧化膜的微观形貌、成分、厚度、耐腐蚀与抗磨损性能的影响。结果表明,复合阳极氧化膜表面吸附一些白色PTFE颗粒,孔洞和凹坑的数量与常规阳极氧化膜相比有所减少,但PTFE乳液体积分数变化会对复合阳极氧化膜的形貌特征、吸附的PTFE颗粒的分布状况、成分、厚度、耐腐蚀与抗磨损性能造成一定影响。添加12 mL/L PTFE乳液制备的复合阳极氧化膜致密性较好,并且表面吸附较多PTFE颗粒(含量接近3%),其厚度约为20μm,腐蚀电流密度仅为9.07×10^(-7) A/cm^(2),并且在相同腐蚀介质中浸泡14 d后整体腐蚀程度最轻,耐腐蚀性能明显好于常规阳极氧化膜和其它复合阳极氧化膜。该复合阳极氧化膜还具有良好的抗磨损性能,磨损量和摩擦系数仅为8.4 mg和0.52,与常规阳极氧化膜相比分别降低45%和29%。

In order to further improve the surface properties of construction aluminum to meet the demanding application requirements,a composite anodized film was prepared on the surface of aluminum from the electrolyte containing PTFE(Polytetrafluoroethylene,abbreviated as PTFE)emulsion,and the effect of volume fraction of PTFE emulsion on the microstructure,composition,thickness,corrosion resistance and wear resistance of the composite anodized film was studied.The results show that some white PTFE particle is adsorbed on the surface of composite anodized film,and the number of holes and pits is decreased compared with that of conventional anodized film.However,the variation of volume fraction of PTFE emulsion has certain effect on the morphology characteristics,distribution of adsorbed PTFE particle,composition,thickness,corrosion resistance and wear resistance of composite anodized film.The composite anodized film prepared from the electrolyte containing 12 mL/L PTFE emulsion has good compactness and more PTFE particle adsorbed on the surface(the content of particle is close to 3%),its thickness is about 20μm,the corrosion current density is only 9.07×10-7 A/cm2,and the overall corrosion degree is the lowest after soaking in the same corrosive medium for 14 days,indicating that the corrosion resistance of the composite anodized film is obviously better than that of conventional anodized film and other composite anodized films.Moreover,the composite anodized film also has good wear resistance,and the abrasion loss and friction coefficient are only 8.4 mg and 0.52,which are 45%and 29%lower than that of conventional anodized film,respectively.