High temperature deformation behavior of Al-Cu-Mg alloys micro-alloyed with Sn

Deformation behavior of Al-6.2%Cu-0.6%Mg alloy and Al-6.2%Cu-0.6%Mg alloy containing 0.06 wt.% of Sn was studied by hot compression tests conducted at various temperatures and strain rates. During the deformation process, the flow stress of the Al-Cu-Mg alloy increased due to trace addition of Sn. The peak flow stress for both the alloys increased with increase in strain rate and decrease in deformation temperature. The peak flow stress during deformation can be correlated with temperature and strain rate by a hyperbolic-sine equation. The activation energy for hot deformation of the Al-Cu-Mg alloy was determined to be 183.38 kJ/mol, which increased to 223.30 kJ/mol when micro-alloyed with 0.06 wt.% of Sn. The Zener-Hollomon (Z) parameter for the two alloys was determined for the various deformation conditions. The tendency of dynamic recrystallization increases with low strain rates and high deformation temperatures which correspond to low Z values. The hot deformation behavior of both the alloys was modeled by suitable constitutive equation. The peak flow stresses at various deforming conditions have been predicted and correlated with the experimental values. It was possible to predict 80% of the values for peak flow stress within an error less than +/- 11.5% for Alloy-A, where as for Alloy-B, 95% of the peak flow stress values could be predicted within an error of +/- 7%. 2010 Elsevier B.V. All rights reserved.