Corrosion and characterisation of dual phase Mg-Li-Ca alloy in Hank's solution: The influence of microstructural features

The influence of the microstructure and the oxide film of the Mg-9.29Li-0.88Ca alloy on its corrosion behaviour was investigated using SEM, EPMA, XPS and corrosion measurements. The results demonstrated that the fine-grained microstructure improved the mechanical and corrosion resistance of the alloy and shifted pitting corrosion to overall corrosion. The oxide film contained a multi-layered structure, with the outer layer being enriched in lithium-bearing compounds; the interior layer predominantly consisting of oxides, hydroxides and carbonates of lithium and magnesium; and the bottom layer containing oxides. The Pilling-Bedworth ratio for chemical compounds was proposed, and the corrosion rates were characterised. (C) 2013 Elsevier Ltd. All rights reserved.