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

• Published in: Modelling and simulation in materials science and engineering 2020-04
• Main Authors: Kartamyshev, Andrey I., Lipnitskii, Alexey Gennadievich, Boev, Anton, Nelasov, Ivan, Maksimenko, Vyacheslav N., Aksyonov, Dmitry Alexandrovich, Nguyen, Truong Khang
• Format: Article
• Language: English
• ISSN: 0965-0393; 1361-651X
• DOI: 10.1088/1361-651X/ab8863

An interatomic potential for the Ti-V binary alloy focusing on 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 DFT data on 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 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.