A comparative first-principles study of tetragonal TiAl and Ti4Nb3Al9 intermetallic compounds. (October 2018) - Wen, Yufeng
Abstract: A comparative study on the phase stability and elastic properties of tetragonal TiAl and Ti4 Nb3 Al9 was performed by first-principles calculations based on density functional theory. The results showed that the stability of Ti4 Nb3 Al9 phase is lower than that of TiAl. The polycrystal Ti4 Nb3 Al9 has the better ductility and the lower hardness, sound velocities and Debye temperature than TiAl. Meanwhile, Ti4 Nb3 Al9 has more significant anisotropy of elasticity than TiAl. The above results can provide a valuable reference for designing the novel γ -TiAl-based alloys with γ 1 -Ti4 Nb3 Al9 phase. Highlights: The stability of tetragonal Ti4 Nb3 Al9 phaseis lower than that of TiAl. Ti4 Nb3 Al9 has better ductility, lower hardness, sound velocities and Debye than TiAl. Ti4 Nb3 Al9 exhibits more significant elastic anisotropy than TiAl. Our researchcan provide a valuable reference for designing novel γplus γ1alloys.