A model for Young's modulus of a particle rein-forced ultrafine grained composite with porosity

In order to investigate the effects of grain size and porosity on the modul us of elasticity of a mechanically alloyed, particle reinforced ultrafine g rained metal matrix composite, a phase mixture model was considered in whic h the composite is treated as a mixture of a matrix phase, a reinforcing pa rticle phase and a porous boundary phase. The boundary phase was assumed to have the mechanical properties of a quasi-amorphous material. Hill's rule of mixtures in conjunction with the phase mixture model was employed. The c alculated Young's modulus was compared with the experimental results. The e ffects of the volume fraction of the reinforcing particles, the overall eff ective density, the grain size of the matrix, and the density of the bounda ry phase on the overall modulus of elasticity are discussed.