Abstract
Proof stress R_p0.2 of dual-phase α + β structured Mg-Li and Mg-Li-Zn alloys has been inspected in terms of the strengthening contributions of α- and β-phases. The alloys studied with variable fraction of α- and β-phases have been subjected to compression straining tests, microhardness measurements and structural analysis by EDX and XRD. Alloying with 1.5 wt.% Zn results in the hardening of both α- and β-phases which however exhibit different hardening responses due to different Zn enrichment. The rule of mixture has been used to interprete R_p0.2 values by taking into account the fraction of α and β phases and their strength level represented by their microhardness. Compression stress-strain curves indicate that work hardening of alloys studied depends considerably on the fraction of α-phase and is higher for Zn containing alloys.

Key words
Mg-Li, Mg-Li-Zn, dual-phase alloy, solution hardening, ageing, work hardening

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