Improving the mechanical properties of pure magnesium through cold hydrostatic extrusion and low-temperature annealing

A way to produce ultrafine grained structure with d ~3 μm and high plasticity in pure magnesium through the original technique of hydrostatic extrusion at room temperature has been demonstrated. The microstructure and the mechanical properties of the extruded magnesium rods have been investigated. The evolution of mechanical properties of the samples after treatments up to 450 °C has been analyzed. It has been shown that low-temperature treatments lead to some increase in strength and plasticity of pre-deformed magnesium. The annealing hardening phenomenon is explained by the thermally activated processes of rearrangement of the dislocation structure and blocking of dislocations.