A molecular dynamics based cohesive zone model for predicting interfacial properties between graphene coating and aluminum

A cohesive zone model (CZM) based on a traction–separation (T-S) relation is first developed to simulate the interfacial behavior between graphene coating and aluminum (Al) substrate. The CZM parameters, which are very difficult to obtain directly experimentally, are determined using molecular dynamics (MD) simulation. Specifically, the MD simulations under the normal and shear loadings are conducted on the graphene-coating/Al interface to derive its T-S relation and then the relevant interfacial behavior of the composite is identified. The MD results show that the behavior of the interface between graphene coating and Al substrate under normal and shear loading is temperature dependent. The maximum normal tensile stress at the interface decreases gradually while the temperature increases from 150 K to 600 K. But the maximum shear stress increases as the temperature increases from 150 K to 450 K and then decreases as the temperature increases from 450 K to 600 K. Finally, the CZM parameters are determined and then imported into a finite element (FE) model. The blister test results obtained by the FE method are in good agreement with those obtained by the MD simulations. These results suggest that the proposed approach is efficient in determining the CZM parameters of the interfacial behavior between the substrate and the ultrathin coating.