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Mg-Li alloy were choosed as experiment alloys in this paper. Influence of Li amounts and heat treatments such as homogenizing and aging on microstructure and mechanical properties of MgLiAlZn alloys were studied. Mg-8Al-0.5Zn, Mg-2.94Li-8Al-0.5Zn, Mg-3.25Li-8Al-0.5Zn, Mg-4.2Li-8Al-0.5Zn were investi-gated systematically to obtain the relationship and interaction of compositon, microstructures and mechanical properties.The alloys are prepared in electrical resistance furnace, and then heat-treated under different conditions. SEM and OM, combined with tensile test are used to analyze the influnce of Li amoutns and heat treatments on microstructure and mechanical properties of Mg-Li alloys.The result shows that: the as-cast microstructure of MgLiAlZn alloy with Li addition are consisted of matrixα-Mg sosoloid,β-Mg17Al12 phases and AlLi phases, the fraction ofβphase decreases andα-Mg matrix is refined. With the increase of Li, the tensile strength and compression strength are increased. After solution treatment the grain size of alloys shows no obvious change and theβphases dissolve into the matrix. After aging treatment theβphases precipitate again, but the amount, size and morphology changes. The hardness values decrease after solution treatment, the compression strength and condensation improve. The hardness values improve after aging treatment, the tensile strength improve, and the ductility of alloy reduce.
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