Atomistic modelling of the γ-TiAl/α2-Ti3Al interfacial properties affected by solutes

Abstract Interfacial properties of γ-TiAl/α2-Ti3Al binary-phase are very important to further understand and design new coating material based on TiAl alloys. In this work, a first-principles methodology has been used to analyze the impact of dilute solutes, including Cr, Nb, Cu, Zn, Si, Mo, and Re that segregated at the interface. It has predicted that the Ti is the preferential site for alloying these elements at the interface layer of γ-TiAl and α2-Ti3Al. Cr, Nb and Mo increase slightly the interface energy leading to decrease stability of γ-TiAl/α2-Ti3Al interface. While Cu, Zn and Si stabilize the phase interfaces. On the other hand, Re atoms have an opposite trend that could stabilize the γ-TiAl/α2-Ti3Al interface when partitioned to γ-TiAl layer and destabilize the γ-TiAl/α2-Ti3Al interface when in α2-Ti3Al layer. The order of cleavage energy from low to high is Re