Structural Stability and Mechanical Properties of Fcc-Fe/TiC Contact Interface by First-Principles Insights

The influence of the precipitation phase on the mechanical properties of austenitic heat-resistant steels is crucial. In this present contribution, the tensile and fracture processes of the fcc-Fe(111)/TiC (111) interface using the first-principles calculation method are investigated from the perspective of atoms and electrons in detail. The results show that the maximum tensile strength of the interface is 49 GPa, and the stress increases with the variation of the strain in the range 0–20%, whereas the stress decreases in the range 20–50% for the strain. The deformation is mainly concentrated in the atomic layer of austenite near the interface, and the atoms on the TiC side do not have obvious deformation. The density of states, differential charge distribution, and population analysis at the interface all reveal that an electron vacancy appears on the austenite side near the interface, and the area becomes clearer with the increase of strain, which weakens the interaction between atoms and reduces the bonding strength. The interfacial structure and the internal atomic structure of the austenite matrix gradually break down with the increase of strain. The results all show that the fracture of the fcc-Fe/TiC interface happens in the atomic layers of the austenite matrix near the interface. The results can provide a basis for the development and design of austenitic heat-resistant steel.