Numerical prediction of the development of particle stress in the forging of aluminium metal matrix composites

Finite element (FEM) techniques for the continuum modelling of thermomechanical processing are well established. This paper describes the coupling of FEM with a microstructural model for the evaluation of particle stress during forging of a metal matrix composite (MMC). High materials cost mean that a good understanding of the effect of the processing route on microstructure is vital. To this end an Eshelby type approach is used to predict particle stress evolution as a response to local variation in stresses, strains, strain-rates and temperatures. These variations are provided both historically and spatially by FEM. It is envisaged that this method will lead to a better understanding of 'damage' modes (particle cracking/debonding etc.) observed at the microscale in MMCs. Preliminary comparisons between optical micrographs of damage in forged MMC components and particle stress maps are presented.