Adhesion and mechanical properties of Fe/SiC interfaces analyzed at the atomic level: Insight from DFT calculations

Abstract

First-principles calculations were conducted to explore the properties of 3C-SiC/Fe interfaces. C-terminated interface exhibits stronger adhesion to iron due to stronger covalent bonding with carbon atoms compared with the Si-terminated interface. Interfacial electronic structure analysis revealed that the ionic attraction between C and Fe atoms significantly contributes to the interfacial adhesion strength. While the interfaces exhibit a mix of covalent, metallic, and ionic bonds, the ionic component is pivotal in enhancing adhesion. Mechanical property analysis revealed that the ideal strengths for cleavage are comparable across different SiC-Fe configurations. However, SiC coatings can improve the overall strength of the cladding at the expense of its ductility due to the polar covalent bonds that weaken metallic bonding. These findings provide insights for the developing corrosion- and radiation-resistant claddings that effectively combine the strengths of metals and ceramics.