Improved ductility in ZM21 magnesium–aluminium macrocomposite produced by co-extrusion

ZM21 magnesium alloy/CP aluminium macrocomposite containing millimetre scale aluminium wire rod reinforcement was fabricated through direct hot co-extrusion. The composite was extruded at 450 °C with three different extrusion ratios (ER) such as 4:1, 9:1 and 16:1 with constant ram speed. The macrocomposite was characterised by microscopy and mechanical testing (tensile and hardness). The characterization proved that the structural integrity between ZM21 Mg alloy and aluminium was good with appreciable grain refinement in ZM21 Mg alloy in all extrusion ratios. Macrocomposite obtained through 16:1 ER exhibited better tensile and yield strength with significant improvement in ductility. The reinforced aluminium in ZM21 Mg alloy significantly contributes the strength and ductility which was confirmed by micrographs and fractographs.