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 (α, α + β, β) were investigated. The result showed that changing Li content can transform the matrix of Mg alloy from α-Mg to β-Li. Except for β-Li, the microstructural morphology of α-Mg is refined by TiB 2 , In the study of corrosion behaviour, a structure of multiple layers is formed on corrosion surfaces, and the α + β alloy has a poor corrosion resistance which results from a mechanism of the dynamic galvanic couple between α-Mg and β-Li. However, the β-Li alloy with high Li content has relatively good corrosion resistance.