A newly developed interatomic potential of Nb−Al−Ti ternary systems for high-temperature applications

Nb-doped TiAl alloys exhibit excellent mechanical properties at high temperatures, and the underlying mechanism and optimal doping amount remain elusive. Molecular dynamics simulation is helpful to clarify these problems, but most of the existing interatomic potentials are limited to the Ti−Al binary system and lack interatomic potentials for doped alloys. Here, an interatomic potential of Nb−Al−Ti ternary systems based on the modified embedded-atom method was developed. The ternary potential can accurately predict the structure and thermodynamic properties of the Nb−Al−Ti system. The potential shows that the optimal Nb content for high-temperature strength-ductility synergy of TiAl single crystals is 8%, consistent with the amount of miracle synthesis of TiAl single crystals. Tensile simulations further show that the developed potential can make an effective prediction at high temperatures, indicating the potential for the development and applications of high-temperature Nb−Al−Ti ternary systems. [Figure not available: see fulltext.].