On effect of particle size distribution on the elastic/plastic deformation of metal matrix composites

Abstract

The elastic-plastic deformation behavior of particulate reinforced metal matrix composites is strongly influenced by not only properties of the metal matrix and reinforcement but also microstructural parameters such as particle size, volume fraction, reinforcement shape and topology that are dependent on the particular processing route used to fabricate the materials. Nan and Clarke have recently developed a hybrid, analytical model by incorporating essential features of both continuum plasticity and dislocation plasticity, which is a combination of the key features of dislocation plasticity with a continuum mechanics approach based on effective medium approximations (EMA). In the present contribution, particular attention will be paid to two problems on the hybrid model. Firstly, the authors introduce a volume-weighted averaging procedure in Nan and Clarke`s methodology and then re-estimate the effect of particle size distribution on deformation in the case of both no damage and including particle fracture. For illustrative and quantitative purposes, the calculations are compared with the experimental results on particular SiC-Al composite by Lloyd. Secondly, the difference between the deformation, secant and the incremental, tangent modulus approaches chosen for EMA modeling is addressed.