A Study of the Corrosion Behavior of Magnesium and its Alloys in Aggressive Environment

Abstract

Magnesium presents indeed a low corrosion resistance [1, 2, 3, 4]. Moreover the behavior of this metal and its alloys is still poorly known in many corrosive environments which limit its applications. Magnesium is particularly sensitive to galvanic corrosion. The presence of impurities (Fe, Ni, Cu, Cr ...) in its matrix with potential higher than that of Magnesium promotes the reduction reactions, especially that of hydrogen and thus generates the galvanic corrosion of magnesium [1, 5]. From its purity depends its resistance to corrosion. The use of alloying elements can improve the corrosion resistance of magnesium (and also the mechanical properties). A beneficial effect of aluminum and manganese on the corrosion resistance of magnesium has been demonstrated [4]. The objective of this work was to evaluate the corrosion of Mg and its alloys by electrochemical method (potentiodynamic) in an aqueous solution of 0.5 M Na2SO4.

Keywords: Corrosion, magnesium, protection, passivation, alloying elements.