FEM modeling of the interface and its effect on the elastio-plastic behavior of metal matrix composites

The interface in a metal matrix composite (MMC) is modeled using finite element method (FEM) to study the deformation behavior of MMCs as a function of interface characteristics such as the interface stiffness and thickness as well as the volume fraction of the reinforcing phase. The interface is modeled as a thin layer of artificial material. The thickness and the modulus of the artificial material are varied as a means to vary the extent of coherency between the matrix and the particles. The effective modulus of MMCs is not significantly altered by the interface modulus as long as it is above ∼25% of the stiffness of the matrix. However, for values below ∼25%, the effective modulus of MMCs is reduced significantly. This effect is seen for a range of volume fraction of the reinforcing phase falling between 5 and 40%. The effect of the interface modulus is noted to be more significant for higher volume fractions of particles and wider spread of the interface. The simulated flow curves are in reasonably good agreement with the experimental ones.