NUMERICAL PREDICTION OF THE DEVELOPMENT OF PARTICLE STRESS IN THE FORGING OF ALUMINUM METAL-MATRIX COMPOSITES

Finite element (FEM) techniques for the continuum modelling of thermom echanical processing are well established. This paper describes the co upling of FEM with a microstructural model for the evaluation of parti cle stress during forging of a metal matrix composite (MMC). High mate rials cost mean that a good understanding of the effect of the process ing route on microstructure is vital. To this end an Eshelby type appr oach is used to predict particle stress evolution as a response to loc al variation in stresses, strains, strain-rates and temperatures. Thes e variations are provided both historically and spatially by FEM. It i s envisaged that this method will lead to a better understanding of 'd amage' modes (particle cracking/debonding etc.) observed at the micros cale in MMCs. Preliminary comparisons between optical micrographs of d amage in forged MMC components and particle stress maps are presented.