First-principles study of interfaces in Al/SiC metal-matrix composite system

First-principles calculations were performed on the interfaces between Al and SiC, which is a widely used strengthening agent in aluminum metal-matrix-composites (Al/MMC). C-terminated interfaces have much larger work of adhesion than Si-terminated interfaces, indicating that the former has much stronger interfacial bonding. The electron localization function shows that the chemical bonding between Al and C has a strong covalent character, while the bonding between Al and Si is largely metallic. As a result of the vastly different chemical bonding, the work of adhesion for C-terminated interfaces increases with the number of dangling bonds at the interface, while the opposite trend was observed for Si-terminated interfaces. Additionally, the interface energy for Si-terminated interfaces is comparable to that for C-terminated interfaces, suggesting both types of terminations can coexist in the Al/SiC system.

Automated summary

First-principles calculations were used to study the interfaces between Al and SiC, a commonly used strengthening agent in Al/MMC. The study found that C-terminated interfaces exhibited higher work of adhesion than Si-terminated interfaces, indicating stronger interfacial bonding. The electron localization function revealed a covalent character for the chemical bonding between Al and C, while the bonding between Al and Si was predominantly metallic. The work of adhesion for C-terminated interfaces increased with the number of dangling bonds at the interface, while the opposite trend was observed for Si-terminated interfaces. Additionally, the interface energy for Si-terminated interfaces was similar to that of C-terminated interfaces, suggesting the coexistence of both termination types in the Al/SiC system.