Corrosion behaviour induced by crystal structure transformation of Mg alloy with AlTiB

The microstructural evolution and corrosion behaviour of three kinds of Mg alloy containing AlTiB (alpha, alpha + , ) were investigated. The result showed that changing Li content can transform the matrix of Mg alloy from alpha-Mg to -Li. Except for -Li, the microstructural morphology of alpha-Mg is refined by TiB2, In the study of corrosion behaviour, a structure of multiple layers is formed on corrosion surfaces, and the alpha + alloy has a poor corrosion resistance which results from a mechanism of the dynamic galvanic couple between alpha-Mg and -Li. However, the -Li alloy with high Li content has relatively good corrosion resistance.