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

ABSTRACT

The Portevin–Le Chatelier effect in an AlCu/Al${}_2$O${}_3$ composite with a large volume fraction (60%) of ceramic particles is investigated from a numerical point of view using a strain-ageing 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.

KEYWORDS:

• Portevin–Le Chatelier effect
• metal matrix composite
• dynamic strain ageing
• statistical analysis

Acknowledgments

A. Mortensen wishes to acknowledge the support of the ++Swiss National Science Foundation, Project No. 200020-107556, and the contributions of Mr F. Juvet and Dr R. Müller, in producing and discussing the pictures in Figure 1.

Disclosure statement

No potential conflict of interest was reported by the author(s).