电解液成分对7075铝合金酒石酸-硫酸阳极氧化膜结构及性能的影响

Effect of Electrolyte Composition on the Structure and Property of the Anodic Film Formed on 7075 Aluminum Alloy in Tartaric-Sulfuric Acid

研究了硫酸及酒石酸浓度对7075铝合金酒石酸-硫酸阳极氧化膜的结构和性能的影响。在酒石酸-硫酸阳极氧化(TSA)体系中处理7075铝合金,采用场发射扫描电镜、纳米压痕仪、电化学阻抗谱等先进分析表征技术研究阳极氧化膜的结构、性能和成膜效率。结果表明:随着酒石酸(或硫酸)浓度的增加,阳极氧化膜的成膜效率及耐蚀性均先升高后降低;当不添加酒石酸或浓度较低时,且硫酸浓度较高时,电解液对阳极氧化膜的溶解作用显著增强,出现疏松的氧化膜结构,当酒石酸浓度为0.5 mol/L、硫酸浓度为120 g/L时获得的阳极氧化膜的综合性能最好。

The influence of sulfuric acid and tartaric acid concentration on the structure and propertiesof tartaric acid-sulfuric acid anodized film of 7075 aluminum alloy was studied.The 7075 aluminum alloy was treated in the tartaric acid-sulfuric acid anodizing(TSA)system,and the advanced analysisand characterization techniques such as field emission scanning electron microscope,nanoindenter,and electrochemical impedance spectroscopy were used to study the structure,performance,and filmformation efficiency of the anodized film.The results show that:with the increase of the amount oftartaric acid(or sulfuric acid),the film formation efficiency and corrosion resistance of the anodicoxide film first increase and then decrease;when tartaric acid is not added or the amount is less,thesulfuric acid concentration is higher At the same time,the dissolution effect of the electrolyte on theanodic oxide film was significantly enhanced,and a loose oxide film structure appeared.Thecomprehensive performance of the anodic oxide film obtained when the tartaric acid concentration was 0.5 mol/L and the sulfuric acid concentration was 120 g/L was the best.