Multiscale modeling of interfacial mechanical behaviours of SiC/Mg nanocomposites

Abstract

The aim of this investigation is to predict the interface separation behavior of silicon carbide (SiC) reinforced magnesium (Mg) matrix composites via multiscale simulations. Interface models for SiC/Mg composites with different interface orientations were first established. The interface crack propagation behaviors and interfacial mechanical properties in the SiC/Mg composites under pure tensile and mixed loadings were then investigated by molecular dynamics simulations. It is found that there are four typical asymmetric crack propagation modes for different SiC/Mg interfaces under pure tension. The interfacial mechanical properties are affected by interfacial bonding characteristics, interfacial orientations and loading modes. A cohesive zone model (CZM) for the SiC/Mg interface was established under mixed loadings and predicted macroscopic mechanical properties of SiC/Mg composites by incorporating the defined CZM in finite element methods are in good agreement with the experimental results. Keywords: Magnesium matrix composites, Molecular dynamics, Interface crack propagation, Cohesive zone model