Hot deformation behavior of hot extruded Al-6Mg alloy

The behavior of hot extruded Al-6Mg during hot deformation has been studied using hot compression test. The tests were performed at temperatures of 350, 450, and 550 degrees C and strain rates of 0.001, 0.1, and 1 s(-1). Due to the effects of friction and adiabatic heating generated during compression, the attained true stress-true strain curves have been corrected. After correction of friction effect, the virtual work hardening has been removed from stress-strain curves. The flow stress increases and reaches a steady state after correction of adiabatic heating effect. Corrected curves and microstructural examinations exhibit the occurrence of dynamic recovery during hot compression of the alloy. The constitutive equation based on corrected curves has been derived for hot extruded Al-6Mg represented by hyperbolic sine equation. The value of hot deformation activation energy is calculated 193.88 kJ/mol. The high value of activation energy is attributed to dislocation pinning caused by solute Mg atoms. (C) 2011 Elsevier B.V. All rights reserved.