Metastability of α/β interfaces in titanium : Implications for interface migration

The interfacial structure of α/β interfaces significantly impacts the mechanical and kinetic properties of titanium and its alloys. This work employs density functional theory to investigate the coherent α/β interface in Ti, focusing on two stable/metastable interface structures, i.e., the Hollow and Bridge (experimentally observed). The relative stability of these two interface states is highly sensitive to in-plane strain. This study also examines the impact of structural metastability on interface migration behavior during the β→α phase transformation. We observe that the Bridge α/β interface migrates easily; the Hollow interface does not migrate; rather, the ω phase forms at the interface. This work also explores the influence of alloying, specifically with vanadium, on the metastability and energy barrier between the two interface states. We demonstrate manipulating α/β interface migration in titanium through strain and doping. © 2024 Acta Materialia Inc.