Finite element simulation of the Portevin-Le Chatelier effect in highly reinforced metal matrix composites

The Portevin- Le Chatelier effect in an AlCu/Al2O3 composite with a large volume fraction (60%) of ceramic particles is investigated from a numerical point of view using a strainageing visco-plastic material model for the metallic matrix and several different finite element meshes based on real microstructures. Even for this very large volume fraction, some serrations are observed on the experimental tensile stress/strain curves, together with the propagation of bands of localised plasticity. The finite element model succeeds in reproducing the serrations and the propagation of bands experimentally observed, and allows a fine analysis of the spatio-temporal evolution of the bands of localised plastic strain rate. Different volume fractions are then virtually generated, tested, and compared to outline the influence of this second phase on the Portevin-Le Chatelier effect.

Automated summary

The study investigates the Portevin-Le Chatelier effect in an AlCu/Al2O3 composite with a high volume fraction of ceramic particles, revealing serrations and propagation of localized plasticity bands even at 60% volume fraction. The finite element model successfully reproduces these phenomena and allows for detailed analysis of the spatio-temporal evolution of localized plastic strain rate bands. Virtual generation and comparison of different volume fractions outlines the influence of the second phase on the Portevin-Le Chatelier effect.