Determination of JMAK dynamic recrystallization parameters through FEM optimization techniques

Abstract

A practical method for determining dynamic recrystallization (DRX) parameters, consisting of finite-element analysis, optimization techniques, and experimental studies, is presented. The method iteratively minimizes the error between target values and the corresponding finite-element solutions using a general-purpose optimization tool. An isothermal hot compression test of AA6060 aluminum alloy was used to investigate the validity of the method. Three main DRX parameters in the Johnson-Mehl-Avrami-Kolmogorov model were obtained using the method, and good agreement was observed between the optimized parameters and reference values from the literature. The effects of mesh size and the number of sample points on the accuracy of the responses were also studied to show the numerical characteristics of the method, revealing that the greater the number of elements and sample points, the more accurate and reliable the results. Parameters acquired using fewer elements also provided acceptable optimized parameters for predicting DRX grain size. (C) 2017 Elsevier B.V. All rights reserved.