A direct method of calculating flow-related dynamic recrystallization parameters for generality and accuracy in predicting microstructural evolution

Abstract

We present a direct method to calculate by which to calculate flow-related dynamic recrystallization (DRX) kinetic parameters, including the peak strain and the strain at 50% DRX which are essential when predicting microstructural evolution. The method is based on an accurate general description of flow curves using the general and improved C-m models in which C and m are defined, at various strains and temperatures, as functions of the strain rate. The method eschews mathematical modeling of these parameters when determining the volume fraction of dynamically recrystallized grains and greatly increases the practical utility of microstructural prediction. A finite element approach based on the direct method and the Avrami kinetic model is utilized to reveal the DRX behavior of the magnesium alloy AZ91D. A comparison among our present approach, other approaches, and experiments reveals that the new method predicts the DRX kinetics and the grain sizes during microstructural evolution with remarkable accuracy.

Keywords

• Direct method
• Flow-related DRX kinetic parameter
• FE prediction of microstructural evolution
• Improved C-m model
• Avrami kinetic model