Corrosion Behavior of Aluminum-Silicon-Copper-Manganese Alloy in Sulfuric Acid Medium

Abstract

The present paper discussed the corrosion behavior of aluminum-silicon-copper-manganese alloy compared with the pure aluminum metal which already reported. Weight loss tests carried out in concentration ratios of H 2SO4 solutions at different temperatures. As a part of the study, corrosion penetration rate determined within interval immersion periods of 5 h. At room temperature, it is observed that aluminum alloys shows decreasing of weight loss and more corrosion resistance in concentrations 10 and 15 % of H 2SO4 solutions compared with the obtained results of pure Al metal. Moreover, corrosion rate increases slightly with increasing concentration of H 2SO4media and the attack is more significant at 50 ∘C. Also, the corrosion penetration rate of Al alloy decreased in the same trend as a result of the formation of thin protective multi oxide films of aluminum, silicon, copper and manganese. Furthermore, the microscopic analysis showed that there is fine pits appeared on the Al alloy surface correlated directly with the increased exposure period in the acidic solution whereas in case of pure Al metal there were a many horizontal streaks formed along the surface.