Response of magnesium microcrystals to c-axis compression and contraction loadings at low and high strain rates

In this work, 99.999% pure magnesium (Mg) single microcrystals have been deformed in [0001] compression (c-axis compression) and [101¯0] tension contraction) conditions at room temperature under loading rates ranging from 5 × 10−4 up to ∼590 s−1. The strain rate sensitivity apparent activation volume of prismatic pyramidal slip systems were evaluated. c-axis contraction, 45 s−1, the formation a new grain whose crystallographic characteristics do not correspond those well-known twin could be observed. An explanation was found but it requires breakdown invariant plane condition, unit cell reconstruction via II basal transformation. This unconventional is 2.1° far classical simple shear on {101¯5} planes. compression, highest applied rate, no detected μm sized pillars 2:1 (height width) aspect ratio. Plasticity thus purely mediated by slip. However, appearance newly oriented grains observed lowering sample size or reducing Their features suggest mechanism through transformation I plane. results presented study impose consider twinning as reorientation necessarily limited shear.