Understanding alloying behaviors of Sc, Ni and Zn additions on Al/TiB2 interfaces based on interfacial characteristics and solute properties

Abstract In this study, the alloying effects of Sc, Ni and Zn elements on both Al(001)/TiB2(0001) and Al(111)/TiB2(0001) interfaces were assessed using first-principles calculations. The most thermodynamically stable Al/TiB2 interface models with Ti terminal and center stacking sequences were selected. To describe interfacial stability and wettability, the interface energy and the work of adhesion were calculated, respectively. For interfacial stability, the alloyed Al(001)/TiB2(0001) interfaces followed the sequence of Ni > Zn > Sc, while an inverse order was found on the alloyed Al(111)/TiB2(0001) interfaces. For interfacial wettability, Sc- and Ni-alloyed Al(111)/TiB2(0001) interfaces displayed an obvious improvement, and the others showed a slight change. The analysis results of chemical bonding and strain distribution illustrated that the alloying effect of Sc and Ni addition mainly relied on the interfacial structure, and the Zn doping interface largely depended on atomic properties. Consequently, the alloying behavior of solute atoms on the Al/TiB2 interface can be explained by the atomic size effect and electronic interaction.