Abstract
The influence of twinning and detwinning on the constitutive mechanical response of Mg was investigated via microcompression tests of single crystalline pillars of nominal [0001] and [10-10] orientations, and bicrystalline pillars containing a single {1 0 1 2} twin boundary. The [0001] pillars exhibit the highest initial yield strength while the [10-10] and bicrystalline pillars initially yield at a significantly lower stress, at which twin nucleation and growth or migration commences. Depending on the extent of straining, the [10-10] and bicrystalline pillars exhibit a secondary yield point associated with the deformation of the newly formed [0001] oriented pillar. The mechanical results point to an anisotropy in the mechanical consequence of twin motion, as characterized through the comparison of the three micropillar orientations; a twin-mediated hardening is indicated by the relative stress-strain behavior.
