MICROSTRUCTURAL DEVELOPMENT DURING HOT-WORKING OF POWDERED ALUMINUM-ALLOY

Microstructural analysis of quenched hot plane strain compression spec imens has revealed key temperatures, strain levels, and strain rates i n the development of the microstructure of compacted aluminium 2014 po wder. The removal of the rapidly quenched cast microstructure in the p owder feedstock, the obliteration of prior powder particle boundaries, the onset of both partial and complete recrystallisation, and the beg inning of hot shortness have been categorised in terms of critical tem peratures, strains, and strain rates. It has been shown that restorati on processes can produce non-uniform microstructures unless certain st rain 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 therm omechanical analysis of metalworking processes such as extrusion and p owder forging.