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Angular dependent interatomic potential for Ti-V system for molecular dynamics simulations


Andrey I Kartamyshev, Alexey G Lipnitskii, Anton O Boev, Ivan V Nelasov, Vyacheslav N Maksimenko, Dmitriy A Aksyonov, Truong Khang Nguyen

Source title: 
Modelling and Simulation in Materials Science and Engineering, 28(5), 2020 (ISI)
Academic year of acceptance: 

An interatomic potential for the Ti–V binary alloy focusing on the evolution of defects, including ones arising as a result of the irradiation process, was constructed within the Lipnitskii–Saveliev approach, which accurately takes into account three-particle interactions and the sum of all multi-particle interactions of a higher order in the framework of the centrally symmetric approximation. In the new potential, Ti–V interactions were fitted to the density functional theory data on a set of model structures with different coordination numbers, including ones with vacancies. The properties used for fitting are accurately reproduced by the present potentials for both pure elements and alloy systems. The potential was tested on the binding energies between Ti atoms and self-point defects in bcc V, elastic moduli, thermal expansion and melting point of some alloys, and diffusion. We obtained qualitative agreement for these properties with available theoretical and experimental data. Finally, we investigated the evolution of excess vacancies in the V–4 at% Ti alloy at 700 K, which are typical conditions of vanadium-based alloys for fusion applications. We found that no vacancy loop is formed in the alloy in contrast to the pure V, which agrees with the experimental observations. The potential is expected to be especially suitable for irradiation simulations of vanadium-based V–Ti alloys.