Multiscale modeling of interfacial mechanical behaviours of SiC/Mg nanocomposites

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. [Display omitted] •Molecular dynamics simulations are conducted using inversion potentials of SiC/Mg interface.•Four typical asymmetric crack propagation modes are found along the interface.•The mixed-mode interface traction-separation law is obtained by molecular dynamics simulations.•Interface failures are affected by interfacial bonding, orientations and loading modes.•Numerical predictions using cohesive zone model are consistent with experiments.