The influence of zirconium additions on the corrosion of magnesium

•The morphology of the Zr present in the Mg–Zr alloys affects the extent and mode of corrosion.•Zr dissolved in solid solution in Mg increases the anodic reaction kinetics.•A greater amount of Zr particles embedded in the Mg matrix increase the cathodic reaction kinetics.•There are more complex interactions that occur in ternary (and higher order) Mg alloys with Zr.

Sixteen custom binary Mg–Zr alloys and four commercial Zr-containing Mg-alloys were used to investigate the role of Zr on the corrosion of Mg. Mg–Zr alloys were manufactured with a range of different Zr concentrations. It was observed that the Mg–Zr alloys with a smaller mean Zr particle size had more Zr dissolved in solid solution. Both the Zr in solid solution and in metallic particle form were observed to have a deleterious effect on the corrosion rate of Mg. However, this deleterious effect is less pronounced to effect in alloys with multiple alloying additions.