Investigation of the Effects of Anodized Surface Coating and Pretreatment Conditions on the Morphology of the Oxide Layer on the Aluminum Surface
Project no. 23859 · Status: Kapanmış (Yayın bekleniyor) · 2022
Summary
<p>In this project, the effects of anodized surface coating and pretreatment conditions on the morphology of the oxide layer on the aluminum surface were investigated. Anodized coating is used to impart corrosion resistance to aluminum. This type of coating, which does not cover the surface of the anodized coating, works inward from the aluminum surface, increases corrosion resistance and improves its mechanical properties. The aluminum oxide layer formed in the anodized coating naturally exists as a thin layer on the normal aluminum surface. This layer cannot provide the corrosion resistance and mechanical properties desired in the industry. Anodizing coating is used to obtain a more permanent and thick aluminum oxide layer. It is desired that the coating thickness is between 5-10 microns. The raw material used in this study is rectangular shaped aluminum parts shaped from 6063 alloy, with and without sanding, used as electrical switches. Sulfuric acid solution was used as electrolyte and conventional anodizing method was applied. Caustic time and chemical polishing time parameters were investigated in order to observe the effects of chemical pretreatments on the anodic oxide layer. Anodizing conditions; electrolyte concentration, electrolyte temperature, anodization time and current to be applied were investigated. Project; preparation of aluminum parts (mechanical pretreatment), chemical pretreatment (surface treatment), anodized coating, fixing process, anodic oxide layer characterization and determination of optimum conditions. The thickness and colors of the formed anodic oxide layers were measured. Fixation was applied to each layer. Color evaluation was also investigated in SEM, AFM, and FTIR analyzes to determine optimum conditions. Optimum conditions were determined by evaluating the anodic oxide layers obtained as a result of the studies. The thickness of the anodic oxide layer formed at a concentration of 150 g/L was obtained as 5.5 microns. As a result of SEM analysis, regular pore formation was observed. A uniform and equal height anodic oxide layer topography was obtained in the AFM analysis. Optimum conditions; 150 g/L electrolyte concentration, 19°C electrolyte temperature, 60 minutes anodization time and 5.5 amp current. Optimum surface pretreatment conditions; caustic time is 180 seconds and chemical polishing time is 10 seconds. The desired results have been achieved.</p>