LAUSR

Abstract The 6xxx series aluminium alloys are extensively used in the structural applications of automobile and aerospace. The strength of these alloys can be further improved by severe plastic deformation. The severely deformed aluminium alloys may experience severe thermal and mechanical process during development of structural components. Therefore, it is important to develop processing map for such severely deformed 6xxx alloys to understand its workability under various temperature and strain rate. In the current work, hot deformation of severely deformed (cryorolled-CR) AA6063 alloy was studied via hot tensile and hot compressive testing in temperature range of 300°C – 450°C and at strain rate of 0.001 s−1 – 10 s−1. The safe processing regions were established via processing map with the help of dynamic materials model (DMM). Also, the constitutive model was established and the activation energies were known to understand the deformation mechanism of CR AA6063 alloy in both tensile and compressive mode. Stable and unstable zones were identified from processing maps in both tensile and compressive mode of deformation. In tensile mode dynamic recovery and in compressive mode simultaneous action of dynamic recovery and dynamic recrystallization were primary mechanisms of deformation in stable region. However, instability region was identified by stress concentration cracking in both tension and compression modes of deformation. The average activation energy in compressive mode (196.57 kJ/mol) of deformation was found to be higher compared to tensile (151.55 kJ/mol) defamation. Microstructural evolution was used to establish a correlation between constitutive model and processing maps.