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This research studies a brand new Magnesium Lithium Alloy, LAZ1151, with trace Sc additions. The mechanical properties and microstructures of the as-cast and alloys after three and six month aging were observed and analyzed. Microstructure and XRD confirms the existence of α phase precipitates (Mg rich) in both as-cast and aging specimens of the alloy. Grain growth was observed in the alloy after room temperature aging. The tensile strength of the as-cast LAZ1151 is 147 MPa; the value is decreased to 135 MPa after six month aging, showing typical room temperature softening. Strengthening via the use of cold rolling was tried; a maximum tensile strength of 180 MPa was achieved after 90% rolling reduction, which is mainly due to strain hardening.

Extremely light (density $1.46 g/cm 3 ) and highly formable Mg-Li alloys have been drawing research interest; however, their relatively low strength is discouraging, and thus, an issue to be addressed. This paper processes and evaluates four Mg-Li alloys: the first, a basic alloy with a nominal composition of Mg-11%Li-1%Al-0.5%Zn; the second, an alloy with only Be added to the first; the third, an alloy with only Sc added to the first; and the fourth, with both Be and Sc added to the first. This research achieves a high strength of $240 MPa for Mg-Li alloys using the processes of solid solution treatment plus 90% heavy rolling. A subsequent natural aging process proceeded spontaneously and resulted in strength decay. Room temperature softening behavior is uncommon, but offers a convenient route for studying age-softening characteristics of metallic alloys.

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