Molecular dynamic simulations of the martensitic transformation for the dual-phase structure and dislocation activities in Ti80 alloys

Abstract

Titanium alloy (Ti alloy) has been widely used in various industry areas and attracted extensive attentions due to their excellent properties. In this work, the martensitic transformation (MT) and complex dislocation activities are thoroughly simulated and analyzed for the commercial Ti80 alloy in molecular dynamic (MD) simulations. One specific interatomic potential is developed for Ti80 alloy within the framework of embedded atom method (EAM), which is capable of describing the related physical properties and the plastic deformation mechanism for this alloy. The stabilities of hexagonal close-packed (hcp) and body-centered cubic (bcc) phase boundary and the martensitic transformation mechanism is fully investigated in MD simulations. The orientation relationship between hcp and bcc phases obeys the Burgers relationship. Complex dislocation activities are reproduced in the simulation of the compression of the polycrystalline configuration, including the formation of dislocation wall, (112‾2) compression twin boundaries and dislocation cross slip mechanisms. The MD simulation results are well agreement with our experimental observations and provides an in-depth understanding of the deformation mechanisms of the Ti80 alloy and related Ti alloys. The revealed deformation mechanism and the newly-developed interatomic potential should be a useful guide to the development of the new series of high-performance Ti alloys in the future.