Plastic deformation and fracture behaviors in particle-reinforced aluminum composites: A numerical approach using an enhanced finite element model

A microstructure-based comprehensive finite element model, which incorporated the deformation/fracture of the matrix alloy, fracture of the particle and decohesion of interface, was built to predict the effects of particle size and shape on the plastic deformation and fracture behaviors in particle-reinforced metal matrix composites. The effect of particle size on the yield strength and work hardening rate of the matrix alloy was demonstrated. When the particle diameter is <10 mu m, the fracture of the matrix alloy near the interface dominates the failure mechanism of the composite, whereas changed to particle fracture with particle diameter >10 mu m. A cohesive zone model was also included in order to predict interfacial failure behavior. It was noted that SiC/Al interface exhibits a high interfacial bonding strength and the interfacial decohesion was caused by crack propagation from the particle to the interface. The simulation results are in good agreement with the experiment tensile test results in the SiCp/6061Al composite.