Influence of extrusion ratio and temperature on microstructure and mechanical properties of 2024 aluminium alloy consolidated from nanocrystalline alloy powders via hot hydrostatic extrusion

Nanocrystalline 2024 aluminium alloy powders with an average grain size less than 50 nm, prepared by a unique technique which combines rapid solidification and mechanical milling, were consolidated into bulk material under various technical conditions via hot hydrostatic extrusion and the microstructure and mechanical properties of the consolidated alloy were experimentally investigated. The influence of the two main technical parameters, extrusion ratio and temperature, on the microstructure and mechanical properties of the as extruded alloy is made clear and the reasons why these two parameters had such an influence on the microstructure and mechanical properties of the alloy are also discussed. Furthermore, suggestions are given for rationalising the extrusion ratio and temperature for the consolidation of the nanocrystalline 2024 aluminium alloy powders via hot hydrostatic extrusion.