A Model for Multi Peak Dynamic Recrystallization in Copper

V.G. García; Jose María Cabrera; Jose Manuel Prado

doi:10.4028/www.scientific.net/MSF.550.565

Paper Titles

A Study of Texture Evolution during Deformation and Annealing in Fe 3 wt.-% Si by Orientation Contrast Microscopy
p.539

Mechanism of Texture Evolution during Primary Recrystallisation and Grain Growth in a Zr-2Hf Alloy
p.545

Texture Evolution in Invar^® Deformed by Asymmetrical Rolling
p.551

Texture Evolution of Tertiary Oxide Scale during Steel Plate Finishing Hot Rolling Simulation Tests
p.557

A Model for Multi Peak Dynamic Recrystallization in Copper
p.565

Modelling Deformation Structures in Metals Based on an Entropic Analysis
p.571

A Fundamental Model of Aluminum Single Crystal Behavior with Physical Description of Kinematic Work Hardening
p.577

Modelling the Deformation and Annealing Processes: Physical and Regression Approaches
p.583

Normal Grain Growth in Three Dimensions: Monte Carlo Potts Model Simulation and Mean-Field Theory
p.589

HomeMaterials Science ForumMaterials Science Forum Vol. 550A Model for Multi Peak Dynamic Recrystallization...

A Model for Multi Peak Dynamic Recrystallization in Copper

Abstract:

Modelling hot flow stress during grain refinement operations of fcc metals has largely included the use of an Avrami type equation to describe the decrease in stress due to Dynamic Recrystallization (DRX). However when refining large-grained copper, the processing temperatures and strain rates often produce a multi peak behaviour, which is not predictable by an Avrami equation alone. If an initial grain size, D0, is greater than the stable dynamically recrystallized grain size, Drex, which is a function of the Zener-Hollomon Parameter, Z, then the material will tend to refine. However if the current the Zener-Hollomon value, given by current temperature and strain rate conditions, is lower than a critical value, Zc, which depends on D0, then a multi peak stress behaviour is expected while refining. The latter Relative-Grain-Size model (i.e. the D0-Zc and Drex-Z relationships plotted on the same log-log graph) is a practical model that allows determination of whether a material will grain coarsen or refine and whether the dynamic recrystallization behaviour will be monotonic or with multi peaks. The present authors devised a dynamic recrystallization algorithm to measure the stress due to the diminishing initial grain volume and to measure the correction stress due to recrystallizing grains. Analysis on the hot (600°C-950°C) compression data of a 99.9% pure copper inductively lead to the use of an Avrami type equation to describe the stress contribution produced by the deformation of the remaining initial grain volume and a damped cosine equation to describe the stress contribution of the synchronized volume of new grains. This work discusses the experimental evidence and analytical findings that inductively support the mathematical description of the stress-strain curve given by a Damped Cosine Avrami Model for discontinuous DRX.