Effect of indentation rate on deformation behavior and mechanical properties of FeO/Fe is simulated based on molecular dynamics

The FeO/Fe bond in the oxide scale is very tight, and FeO fracture is complicated under external force. In this study, the deformation behavior and mechanical properties of single-crystal FeO/Fe under nanoindentation are analyzed by the molecular dynamics (MD) simulation method. The results show that: 1. loading stage: the load increases with the increase in the loading rate; unloading stage: the load drop rate increases with the increase in the unloading rate in the early stage, and the opposite in the middle and late stage. 2. The dislocation density and the phase transition of the HCP structure decrease with the increase in the indentation rate, and the total volume of defect atoms increases with the increase in the indentation rate. 3. When the indenter is in the FeO layer, the hardness and elastic modulus increase with the increase in the indentation rate. 4. The hydrostatic stress and Von Mises stress analysis show that the average stress value increases with the increase in the indentation rate, and coexistence of compressive and tensile stress inside the model. This study provides essential help for further exploration of the deformation behavior and mechanical properties of oxide scales.