Effect of backward extrusion on microstructure and mechanical properties of Mg-Gd based alloy

► Backward extrusion can improve mechanical properties of Mg-RE alloys greatly. ► Precipitates and ageing in backward extruded sample are the same as the as-cast one. ► The peak-hardness time is shortened greatly after backward extruded deformation. ► The high elongation is related to fine precipitates and uniformed small grain size.