Microstructure and Mechanical Properties of Mg-Li-Al-Mn-Si-Ca Alloy

The microstructure and mechanical properties of Mg-Li alloy were studied after adding the trace elements Al,Mn,Ca and Si in it.The alloy thus has a good cold-workability to roll it into 2?mm thin sheet at room temperature.The effects of Al,Mn,Si and Ca on the microstructure and mechanical properties of the sheets was investigated metallographically.It was found that adding these elements in the alloy can refine α phases with granular and strip-like substances produced,which are proved to be some new compounds formed between different added elements by the observation using optical microscopy and SEM with EDX analysis.Tensile tests were carried out at room temperature and the results showed that the Al,Mn,Ca and Si additions can all improve the tensile strength and percentage elongation of the alloys,and the more the different elements added in,the higher the alloy strength,and finally the σ_(0.2) and σ_b increase by 17.06% and 13.16%,respectively,when adding 1wt%Al,0.2wt%Mn,0.1wt%Ca and 0.1wt%Si,but the high percentage elongation decreases to some extent.This is just the reason why the added elements form new phase and strengthen the alloys.