Abstract:

First-principle approach based on density functional theory and experimental method were used to study the interface bonding of SiC/Al substituted by alloy elements Mg, Si and Cu. The electronic structure and bonding of alloy elements at interface segregation were investigated. The results show that bridge-site model with bridge Si is the most stable combination way of SiC/Al interface after optimization of the interface structure of pure Al/SiC system. When Al atoms at the interface replaced by alloy elements separately, the electronic structural parameters such as partial density of states, Mulliken charge and bonding population, all vary in different degree, which not only increase the binding of Si and Al atoms at the interface, but also increase the interaction among alloy atoms, Al matrix and SiC reinforcement at the interface and sub-interface. It is conducive to enable the system more stable and the adhesion work of interface more differently. Among them, the increased adhesion work is the most obvious when Mg is doped, followed by Cu and Si. Furthermore, the adhesion work of Al/SiC systems doped alloy elements calculated by first-principle is close to the experimental values, and the law of change is the same.

Key words: alloy element, SiC/Al interface, interface bonding, first principle