The Influence of Electric Current and Electrolyte Solution on Porous Characteristics on Aluminum Anodizing

Abstract

Abstract For decoration purposes, aluminum metal has widely used metal coloring techniques to enhance the aesthetic value of the metal. Most coloring techniques of the aluminum metal use aluminum metal dipping with dye or with chrome (Cr) directly. This coating technique has the disadvantage, such as the color fade easily or the chrome layer peels off. The anodizing method becomes a potential method to improve coloring techniques because this process is able to provide a protective layer and improve surface appearance through staining and can change the aluminum surface to aluminum oxide, high hardness, and corrosion resistance. This study aims to analyze the surface condition of the aluminum after the anodizing process with several variables. In this research uses the variation of H2SO4 electrolyte solution concentration and electric current as variables to improve aluminum surface quality. Anodizing process is carried out with electrolyte concentration up to 20% and current up to 5 A. The Characteristic of an aluminum oxide layer is tested using hardness test, optical and Scanning Electron Microscope to observe the hardness, the pores distribution and the average of pores diameter. The results of the hardness show that increasing electric current will decrease the hardness of the Aluminum surface. The significant results are also showed in electrolyte concentration variables, increasing electrolyte concentration will reduce hardness and enlarge pores diameter.