Size effects in metal matrix composites

The mechanical properties of Al / Al 2 O 3 metal matrix composites are investigated using a 3D discrete-continuum simulation of dislocations and plasticity. The variations of the yield stress as a function of fibre volume fraction can be predicted from Orowan’s law. The dependence of internal stresses on fibre volume fraction leads to a size effect resulting from a virtual decrease of the channel width between fibres.