The Effects of Fe and Si Elements on Structural, Mechanical, and Electronic Properties of an Fe–Si–Ti System by First-Principles Calculations

Herein, first-principles calculations with density functional theory are used to investigate the structural, mechanical, and electronic properties of Fe–Si–Ti alloys, aiming to study the effects of Si and Fe in titanium alloys. The calculated lattice parameters are in good agreement with previous data. Alloying with Si/Fe can produce more brittle/ductile materials, due to the weaker/stronger metallic bonds. Furthermore, the effect of alloying with Si and Fe on the anisotropic properties is negligible. The increasing range of Debye temperatures by alloying with Si is greater than that by alloying with Fe. The capacity of Si to enhance the interatomic bonding force is greater than that of Fe due to the stronger covalent bonds. Similarly, the charge density reflects that the capacity of Si to enhance the interatomic bonding force is better than that of Fe for titanium alloys. In addition, the metallic conductivity of these alloys is verified, with there being no gaps at the Fermi level. The localization of electrons in the SiTi alloy is observed to be relatively strong around the Fermi level. In addition, the amplitude of the top of the valence band and the bottom of the conduction band is smooth, showing great effective mass.