Novel on-line twist extrusion process for bulk magnesium alloys

This study presented a novel intense plastic straining process called on-line twist extrusion (OLTE). An on-line torsional strain was applied on magnesium extruded rod during extrusion. After OLTE, the grains are refined from the periphery to the center of the bar, and the refined extent can be promoted with increased torsion speed. A fully recrystallized ultrafine grained structures and spiral shaped basal texture with the average grain size of 1.2 μm are successfully achieved with increased torsion speed. The microstructure evolution and strengthening mechanism were also discussed.