Stabilization of metastable phases in Mg–Li alloys by high-pressure torsion

In this work we demonstrate that pure compression of the single phase bcc Mg–12 wt.% Li and Mg–20 wt.% Li alloys in a high-pressure torsion system induces the precipitation of hexagonal close-packed (hcp) Mg and hcp Li-rich phases, which remain stable under ambient conditions. This transformation is enhanced with increasing pressure. Shearing under pressure of the multiphase microstructure results in the dissolution of the metastable hcp phases and the subsequent growth of the bcc matrix grains.