Large deformability of Mg alloys produced by confinement to the nanoscale in one dimension

摘要

We report a transition to large-strain, multi-slip plasticity in Mg alloys resulting from refinement of a single dimension of the deformation geometry to the similar to 100 nm-scale. Basal-slip-dominated strain localisation and fracture is suppressed and shear strains greater than 200% are realised at ambient temperatures when one characteristic dimension is refined in an asymmetric wedge indentation, even when the other two dimensions remain macroscopic. The ductility at sub-critical scales of low dimensionality discovered here is independent of crystal orientation, and interfaces and large shear strains result in homogeneous nanocrystallinity in the deformed material under these conditions.