Prediction of corrosion rate of AZ31B magnesium alloy under salt fog environment in NaCl solution

Abstract

Magnesium alloys have gained considerable interest as a material for automotive and aerospace applications due to its low density, high specific strength, and good castability. However, another considerable issue is their corrosion properties. This restricts their practical applications. In this present research, corrosion behavior of the AZ31B magnesium alloy was evaluated by conducting salt fog test in NaCl solution at different chloride ion concentrations, pH values, spraying times, and air pressures. The corrosion morphology observation was carried out by optical microscopy and the corrosion products were analyzed by SEM and XRD analysis. An attempt was also made to develop an empirical relationship to predict the corrosion rate of AZ31B magnesium alloy. Four factors five level central composite rotatable design matrix was used to minimize the number of experimental conditions. Response surface (RSM) methodology was used to develop the relationship. The developed relationship can be effectively used to predict the corrosion rate of AZ31B magnesium alloy at 95% confidence level.

Keywords

• Magnesium alloy, chloride ion concentration, response surface methodology, corrosion rate

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