Effect of Oxygenated Additives on the Corrosion Behavior of Al-Si-Cu Alloy in Synthetic Condensed Automotive Solution

This work involves studying the effect of adding alcohols on corrosion behavior of Al-Si-Cu alloy in synthetic condensed automotive solution (CSAS) at room temperature. Alcohols used were methanol (MeOH), ethanol (EtOH), porpanol (PropOH), Butanol (ButOH), and mixture of (MeOH-EtOH), (MeOH-PropOH) and (MeOH-ButOH). According to potentiodynamic polarization test, the results of corrosion resistance indicate that additive alcohols increase the resistance of Al-Si-Cu alloy, except addition of ethanol to the CSAS and the resistance follows the sequence: MeOH. ButOH MeOHButOH MeOH-PropOH PropOH MeOH-EtOH. Cyclic polarization measurements were carried out to estimate the pitting resistance of Al-Si-Cu alloy in CSAS in the absence and presence of alcohols, this test shows that the hysteresis loop appears only in cases of presence of ethanol and (MeOH-EtOH) mixture in CSAS indicating the disadvantage of adding ethanol and (MeOH-EtOH) mixture to automotive fuel.