Nanoindentation behavior and deformed microstructures in coarse-grained magnesium alloys

Nanoindentations at both low and high rates are used to study deformation of Mg and some dilute solid-solution Mg alloys with coarse grains ∼100 μm in size. Unlike prior reports in fine-grained alloys, post-deformation microstructural observations reveal the formation of {101¯2} twins. These twins are proposed to form early during indentation, leading to strain compatibility constraints that promote cross-slip with a characteristic activation volume between 40 and 100b3 in the strain rate range of 0.02–170 s−1.