On the Ductility of Magnesium Single Crystals at Ambient Temperature

Magnesium single crystals were loaded in plane-strain compression at ambient temperature, parallel, and normal to the c-axis. In the latter configuration, compression was applied along the 〈\( 11\overline{2}0 \)〉 as well as 〈\( 10\overline{1}0 \)〉 directions, whereby extension was confined to the c-axis owing to the plane-strain geometry. Out of the three tested orientations, only specimens compressed along the 〈\( 11\overline{2}0 \)〉 axis were able to deform up to a remarkable strain of −1 demonstrating a surprisingly high ductility for pure magnesium at ambient temperature. The other two specimen orientations have depicted failure at two different low strains. The final microstructure of the ductile specimen was a polycrystalline mix of large deformed grains adjoining recrystallized regions of much finer grains, developed by means of extensive dynamic recovery. The corresponding final texture was relatively weak, and showed two orientation peaks with appreciable scatter around them.