Mixed mode I/III fracture toughness in extruded magnesium alloys

► Texture developed on extrusion in Mg alloys is dependent on the alloying additions. ► Axial texture in extruded Mg and Mg-1.25Zn alloy promotes deformation twinning. ► The presence of deformation twins promotes early fracture. ► Fracture toughness under mixed mode loading is higher for Mg and Mg-1.25Zn alloy. ► Fracture toughness under mixed mode loading is lower for Mg-1Al and Mg-3Al alloy.