THE EFFECT OF ELECTROPOLISHING ON THE ANODIC FILM AND ITS ELECTROLYTIC COLORING FROM A SECONDARY ANODIC PROCESS

• Main Authors: Yao-Hsiang Hu, 胡曜翔
• Other Authors: Hsing-Hsiang Shih
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/mx7esy

碩士 === 大同大學 === 化學工程學系(所) === 102 === The study was carried out by means of the method of electropolishing on the anodic films before secondary anodic treatment and then electrolytic coloring in cupric sulfate solution. It is expected that by this method a dense and regular oxidizing film on aluminum can be obtained and that the optimum operating conditions for obtaining a blackest film are found out. The experimental results show that electropolishing on the anodic films increase the size of pores and more regular, the secondary anodic treatment can also increase the size and the number of pores, after electropolishing and secondary anodic treatment on aluminum sheets make the thickness of the anodic colored film become thicker. From SEM and AFM we found the pores are larger and more than anodic treatment, secondary anodic treatment, and anodic treatment after electropolishing, also has a good effect for electrolytic coloring. We get the lowest ΔΕ*and reflectivity after coloring, but the hardness of the anodic colored film become lower. The optimal operating conditions for obtaining the blackest colored film are: electropolishing voltage 10Vdc, electropolishing time 30 min in phosphoric acid and ethanol, secondary anodic treatment current 2A/dm2, secondary anodic treatment time 30 min, electrolytic coloring voltage 20 Vac and electrolytic coloring time 120 minutes, the lower △E value, and reflectivity would be obtained. Those values are respectively 9.96 and 5.4%.