Microstructure and texture development during deformation and recrystallisation in strip cast AA8011 aluminum alloy

Abstract

In the present work, microstructure and texture development during deformation and recrystallisation of a twin roll cast (TRC) AA8011 aluminum alloy was investigated. TRC AA8011 alloy with initial thickness 7.2 mm and Fe:Si ratio ∼0.93 was cold rolled in a laboratory rolling mill to 2 mm final thickness. The cold rolled sheet was recrystallized at 375 °C and 450 °C for different times. The hardness decreased with increase in recrystallisation time for both temperatures, but there was no effect on centre line segregation (consisting predominantly of Al-Fe-Si intermetallics). XRD confirmed the presence of β-AlFeSi particles at all the stages of recrystallisation. The initial TRC sheet had a very weak texture close to brass ({110}<112>). After 72% cold rolling (final thickness, 2 mm), strong brass, copper ({112} <111>) and S ({123}<634>) texture i.e. metal type texture developed. Low temperature annealing (4 h at 375 °C) was found to give optimum combination of deformation texture and cube recrystallisation texture ({100} <100>) expected to improve the forming behavior of cold rolled and annealed sheet.