A study of annealing stages in Al–Mn (3004) alloy after cold rolling using positron annihilation lifetime technique and Vickers microhardness measurements

Positron annihilation lifetime (PAL), scanning electron microscope (SEM) and Vickers microhardness (Hv) measurements have been performed to study the isochronal annealing of Al–Mn (3004) alloy in the temperature range from RT to 823 K after cold rolling at RT with various deformations of 7 and 23%. A positive correlation has been found between average lifetime (τav) of positrons and Vickers microhardness. annealing stages of microstructures in Al–Mn (3004) alloy were distinguished which were attributed to recovery, partial recrystallization and complete recrystallization followed by grain growth. It appears that high cold work accelerated recystallization process while low cold work accelerated recovery process.