对铝在磷酸和钨酸钠体系中的高压氧化行为进行了研究.结 果表明其氧化行为可以分为四个阶段 ，即常规阳极氧化阶段、膜层沉积的初始阶段、快速增厚阶段和缓慢生长阶段.第一阶段形 成的氧化膜与在单独的磷酸或钨酸钠体系中形成的氧化膜有所不同.扫描电镜(SEM)结果表明 ,氧化膜微观结构呈“羊毛线头”，这些羊毛线头在电压升高时聚集、交织成网架结构，为 膜层的沉积作准备.溶液中的电解质粒子，如WO2-4、PO3-4等阴离子，在 界面电化学及焦尔热的联合作用下絮集于网架状氧化膜表面，并经浓缩、凝聚、脱水和快速 冷却，形成了具有特殊结构的非晶态的网状转化膜.
High voltage anodization of aluminum in mixed elect rolytes of phosphoric acid and sodium tungstate could be divided into four stage s: conventional anodization stage,initial stage of anodic deposition,rapid growt h stage and slow growth stage.The film formed during the first stage was differe nt from that formed either in phosphoric acid or sodium tungstate electrolyte.SE M results showed that it had a woolenlike microstructure and quickly interlace d into a web in the second stage with the increase of the voltage.The electrolytic spe cies such as PO3-4、WO2-4 and et al,aggregated toward the gel fo rmed near the oxide and transformed to the noncrystalline film through concentra tion,coagulation,dehydration and refrigeration under the combined action of elec trochemical and Joule heat effects.
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