Constitutive equations for high temperature flow stress prediction of Al-14Cu-7Ce alloy

In order to find material parameters of established Zener-Hollomon constitutive equations and predict high-temperature flow stress of Al-14Cu-7Ce alloy, isothermal hot compression tests were conducted using a Gleeble 3500 thermomechanical simulator at constant stain rates of 0.001, 0.01, 0.1 and 1 s(-1) and at temperatures ranging from 300 to 550 degrees C at intervals of 50 degrees C. The effects of strain rate and temperature on hot deformation behavior were represented by Zener-Hollomon parameter including Arrhenius term. Four material constants alpha, n, A and activation energy Q in the equations were calculated by compensation of strain. The results show that the proposed constitutive equations give a precise estimate for high temperature flow stress of Al-14Cu-7Ce alloy, which means it can be used for numerical simulation of hot deformation process and for choosing proper deformation parameter in engineering practice accurately. (C) 2011 Elsevier B.V. All rights reserved.