MICROSTRUCTURAL DEVELOPMENT DURING HOT-WORKING OF POWDERED ALUMINUM-ALLOY

Microstructural analysis of quenched hot plane strain compression specimens has revealed key temperatures, strain levels, and strain rates in the development of the microstructure of compacted aluminium 2014 powder. The removal of the rapidly quenched cast microstructure in the powder feedstock, the obliteration of prior powder particle boundaries, the onset of both partial and complete recrystallisation, and the beginning of hot shortness have been categorised in terms of critical temperatures, strains, and strain rates. It has been shown that restoration processes can produce non-uniform microstructures unless certain strain rates are achieved. Such microstructural surveys, conducted under controlled conditions, produce reference micrographs that can be used as independent checks on the frequently used models employed in thermomechanical analysis of metalworking processes such as extrusion and powder forging.