Ab initio modelling of titanium impurities in α-Fe lattice

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Beam interactions with materials and atoms, 2020-11, Vol.483, p.50-54
• Main Authors: Sokolov, M.N., Mastrikov, Yu.A., Gopejenko, A., Bocharov, D., Zhukovskii, Yu.F., Kotomin, E.A.
• Format: Article
• Language: English
• Subjects: Defect interaction energies; DFT calculations; ODS steel; Ti impurity; α-Fe
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2020.09.013

Reduced activation ferritic-martensitic (RAFM) as well as ferritic steels strengthened by yttrium oxide are considered as candidate materials for future fusion and advanced fission reactors. Addition of Ti during the manufacturing of the oxide dispersed strengthened (ODS) leads to the formation of yttrium titanium oxide particles, which size is smaller compared to yttrium oxide particles. This improves the mechanical properties and radiation resistance of the ODS steels. DFT calculations of Ti impurities have been performed to determine the factors contributing to the formation of the nanoparticles in α-Fe (bcc-Fe) based steels. The interaction energies between TiFe-OFe, TiFe-Ooct, TiFe-TiFe, TiFe-YFe, and TiFe-VFe have been calculated. The obtained results point to the noticeable interactions of the point defects up to the second nearest neighbours for the most of the defect combinations considered and could be used in following lattice kinetic Monte Carlo (LKMC) modelling of the ODS particle formation process in ODS steels.