绝缘保护用铬酸阳极氧化工艺研究  

Research on Chromic Acid Anodizing Technique for Insulation Protection

作　　者：刘静 马小昭 王帅星[2] LIU Jing;MA Xiaozhao;WANG Shuaixing(AECC Xi'an Power Control Technology Corporation,Xi’an 710077,China;School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]中国航发西安动力控制科技有限公司,陕西西安710077 [2]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《电镀与精饰》2022年第6期41-46,共6页Plating & Finishing

摘　　要：航空上大量铝合金零件在铬酸阳极氧化后需进行局部硬质阳极氧化,现有的涂蜡/胶方法工艺流程长且易造成硬质阳极氧化膜白斑缺陷,有必要开发一种绝缘保护铬酸阳极氧化工艺。本文重点从槽液杂质控制、升压方式调整、封闭方法优化等角度研究了相关因素对氧化膜厚度、耐绝缘击穿性能的影响,确定了绝缘保护铬酸阳极氧化工艺并评价了其应用效果。结果表明:通过控制铬酸阳极氧化溶液中Cl^(-)、SO_(4)^(2-)含量分别在0.1 g/L、0.4 g/L以下,采用二次升压法进行阳极氧化可获得4~6μm厚的氧化膜;同时经沸水和醋酸镍双重封闭后,氧化膜的耐绝缘击穿性能大幅提高,最小绝缘电压大于90 V,且可通过800 h的中性盐雾试验。新型绝缘保护铬酸阳极氧化工艺,大幅缩短了局部硬质阳极氧化工艺流程,且可完全消除涂蜡造成硬质阳极氧化膜层白斑及白点缺陷,应用效果显著。In the aviation field,many aluminum alloy parts need to be localized hard anodic oxidation after chromic acid anodizing(CAA).At present,overlaying wax or glue is widely used for the protection of non-hard anodic parts,but this process is long and easy to cause the white spot defect of hard anodic film.Therefore,it is necessary to develop an CAA technique for insulation protection.In this paper,the control of bath impurities,the adjustment of the boosting method,and the optimization of the sealing method were emphatically researched,and the influence of these factors on the thickness and insulation breakdown resistance of the oxide films was analyzed.Subsequently,the CAA process for insulation protection was determined and its application effect was evaluated.The results showed that if the Cl^(-)and SO_(4)^(2-)content in the anodizing solutionwere controlled to be below0.1 g/Land 0.4 g/L,and the second step-up method was used for anodizing,an oxide film with the thickness of 4‒6μm could be obtained.Meanwhile,when CAA film was double-sealed with boiling water and nickel acetate,its insulation breakdown resistance was greatly improved,theminimum insulation voltage was above 90 V,and it could pass the neutral salt spray test of 800 h.The new CAA technique for insulation protection greatly shortened the local hard anodizing process,and could completely eliminate the white spots of the hard anodic film caused by coating wax,and the application effect was remarkable.

关 键 词：铝合金 硬质阳极氧化 铬酸阳极氧化 二次升压 封闭 绝缘电压 

分 类 号：TG174.451[金属学及工艺—金属表面处理]