Microstructure and texture development in AA3003 aluminium alloy

Abstract

For good deep drawability in aluminium and its alloys, a proper balance of deformation and recrystallization texture components is essestial in the final material. This balance of deformation and recrystallization texture can only be achieved by properly controlling the thermo-mechanical processing of the alloy. In the present study, microstructure and texture development during casting, hot rolling, cold rolling, and annealing of an aluminium alloy (AA3003) is investigated. The cast microstructure showed large grains with average grain size 111 μm and presence of Al-Fe-Si particles along the grain boundaries. After hot rolling (500 °C (±10 °C)) and cold rolling, these second phase particles which consisted primarily of Fe:Si in a ratio 10:1 in the as-cast microstructure fragmented into smaller particles and had higher percentage of Fe, Mn, and Si. After hot rolling and cold rolling, microstructure showing banded structure along the rolling direction i.e. elongated grains. Annealing at 450 °C for 16 h produced microstructure with uniform average grain size 22 μm and second phase particles with non-uniform size distribution. The initial as-cast AA3003 alloy had a very weak cube texture ({100}<100>, 3.4 % volume fraction). After cold rolling, strong Brass ({110}<112>), Copper ({112}<111>) and S ({123}<634>) components formed. After cold rolling, cube decreased and did not improve significantly even after annealing at 450 °C. The developments in annealing texture is explained on the basis of particle stimulated nucleation.