Modelling microstructure evolution in polycrystalline aluminium -Comparison between one- and multi-parameter models with experiment

摘要

The plastic response of an aluminium alloy type A6061 is modelled using different state parameter-based approaches. Several of these models (one- and two-parameter models) have recently been implemented into the thermo-kinetic software package MatCalc. In the present work, a model based on the Kocks-Mecking-law is used to investigate the capabilities of one and two parameter approaches in order to model experimental data. The experimental work presented here is performed on a Gleeble 1500 thermo-mechanical simulator for different natural ageing times. We demonstrate that one-parameter models offer a ready-to-use and easy-to-calibrate solution for a rough correlation between flow-curve data and microstructure. Such models describe the evolution of the average dislocation density in time. In many practical cases, a single state parameter is insufficient and multi-parameter models must be utilized, for instance, with consideration of separate populations of dislocations in walls and subgrain interior. These approaches can consistently represent the deformation behaviour of alloys in a variety of conditions with respect to temperature and strain rates.