Modelling of microstructure effects on the mechanical behavior of aluminium tubes drawn with different reduction areas

•We investigated the microstructure and mechanical properties of cold-drawn aluminium tubes.•We determined the contribution of the dislocation density to strength of deformed tubes.•We modeled the effects of grain size and strengthening contribution on the mechanical behavior of drawn tubes.•We identified the parameters of micromechanical model.

The elastoplastic self-consistent model is one of the effective models to study the initial microstructure effect on the mechanical behavior of bulk materials. However, the use of this micromechanics-based model which only takes into account the Hall–Petch relationship at grain level for predicting the grain size effects on the strength of the deformed materials is not accurate yet. This is because of the fact that the dislocation density also contributes to the strengthening of deformed materials. In this study, a modification made to the Hill-Hutchinson elastoplastic self-consistent model was proposed for investigating the microstructure dependence of the mechanical behavior of deformed materials. Meanwhile, the application of the proposed model for the prediction of mechanical behavior of cold-drawn 6063 aluminium tubes with variable wall thickness was studied. Because of the novel modification, an optimization procedure with two objectives was required to identify the parameters of this micromechanical model. An acceptable agreement between experimental and theoretical stress-strain curves was achieved.