Abstract
High temperature deformation behavior of 6082AA that was over aged and pressed to 6 passes in equal channel angular die via route C was investigated. High-temperature tensile deformation was conducted in the range of 753 to 823 K at four strain rates in the range of 10(-2)-6 x 10(-1) s(-1). Stress dependence of the strain rate revealed a stress exponent, n of 7 throughout the ranges of temperatures and strain rates tested. The apparent activation energy was calculated to be 223 kJ mole(-1). These findings implied the presence of threshold and by incorporating the threshold stress in the analysis, the true activation energy was calculated to be about 139 kJ mol(-1). A plot of normalized strain rate ((epsilon) over dotkT/DGb) vs. normalized effective stress (sigma-sigma(o))/G, on a double logarithmic scale, gave an n value of 5. Ductility increased with strain rate for all the temperature ranges and maximum ductility value of 173% was achieved at 823 K for 6 x 10(-1) s(-1). (C) 2012 Elsevier B.V. All rights reserved.