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 les s than 50 nm, prepared by a unique technique which combines rapid solidific ation and mechanical milling, were consolidated into bulk material under va rious technical conditions via hot hydrostatic extrusion and the microstruc ture and mechanical properties of the consolidated alloy were experimentall y investigated. The influence of the two main technical parameters, extrusi on ratio and temperature, on the microstructure and mechanical properties o f the as extruded alloy is made clear and the reasons why these two paramet ers had such an influence on the microstructure and mechanical properties o f the alloy are also discussed. Furthermore, suggestions are given for rati onalising the extrusion ratio and temperature for the consolidation of the nanocrystalline 2024 aluminium alloy powders via hot hydrostatic extrusion.