Influence of alloy atoms on the electronic structure and interfacial properties of graphene/aluminum composites: Theoretical calculation and experimental verification

Abstract

The addition of graphene in Al-based composites results in the creation of a high-content interface, which serves as the primary contributor to the reinforcement performance of the composites. Nevertheless, the reinforcing agent at the nanoscale level exhibits extremely high reactivity, making it prone to reacting with the Al matrix at the interface and producing the brittle phase Al4C3. In this paper, the electronic structure and interface stability of the graphene/aluminum with alloy atoms were systematically studied using first-principles calculation based on density functional theory. The interactions of four different alloying atoms (Mg, Cu, Ti, and Ni) were analyzed, the results show that the four metal atoms exhibit varying levels of micro-alloying, and the coating of alloying atoms enhances the interfacial bonding stability. The band structure calculations of interfacial configurations with alloy atoms (Mg, Cu, Ti, Ni) indicate that Cu and Mg have little impact on the integrity of graphene layers at the interface, while Ni and Ti are detrimental to the integrity of graphene at the interface. The composites were fabricated through a process of vacuum hot-press sintering, and a series of characterization experiments were conducted to confirm the accuracy of our calculations. This study offers theoretical guidance for future development of aluminum alloy composites by exploring the impact of alloying atoms on the stability and electronic structure of the graphene/aluminum alloy interface.