新型Mg-Li-Al-Mn-Si-Ca合金的显微组织和力学性能

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

向Mg-Li合金中添加微量元素Al,Mn,Ca和Si,研究了合金的显微组织与力学性能.室温下合金具有良好的加工性能,能够轧制成薄板.通过金相观察可知,添加元素能够细化组织中的α相,并生成颗粒状及细条状物质,通过SEM和EDX分析可知,其为不同添加元素之间形成的化合物.室温下拉伸测试结果表明,合金具有较高的强度和延伸率,随着不同元素的逐步添加,合金强度不断提高,最终σ0.2可以提高17.06%,σb可以提高13.16%,而延伸率有所降低,但仍具有较高值,这是添加元素强化的结果.

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 AI, Mn, Si and Ca on the microstructure and mechanical properties of the sheets was investigated metallographieally. It was found that adding these elements in the alloy can refine a 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 AI, 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 σ0.2 and σb 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.