Energy and Surface Quality Analysis of AA6063 Alloy During Sulfuric Acid Anodizing at Different Bath Temperatures
Abstract
This study investigates the influence of anodizing bath temperature on coating properties, microstructure evolution, and cooling energy demand during sulfuric acid anodizing of AA6063 aluminum alloy. Experimental studies were carried out using 20 wt.% sulfuric acid electrolyte at a constant current density of 15 A/dm² and anodizing duration of 30 minutes. Coating thickness, Vickers microhardness, and scanning electron microscopy (SEM) analyses were performed to evaluate the coating quality. In addition, a thermodynamic cooling load model was developed to estimate the energy consumption of the anodizing bath cooling system. Results indicate that bath temperature significantly affects oxide layer morphology, pore structure, and mechanical properties. It has been observed that the coating thickness increases as the anodizing bath temperature increases. Microhardness values ranged from 459 HV to 534 HV, depending on process temperature. SEM observations revealed homogeneous pore distribution at 19–20°C, while dissolution effects became dominant at 22°C. Energy analysis showed that increasing bath temperature from 18 °C to 20 °C reduces cooling energy demand by approximately 17%. The combined analysis suggests that the optimal operating window for AA6063 sulfuric acid anodizing is between 19 °C and 20°C, providing a balance between coating quality and energy efficiency.
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