Eur. Phys. J. B (2022) 95: 83
https://doi.org/10.1140/epjb/s10051-022-00347-4

Regular Article - Computational Methods

Structural, elastic and mechanical properties of Hf-doped TiAl₂ and α-TiAl₃ intermetallic compounds: first-principle calculations

¹ Department of Metallurgical and Materials Engineering, Faculty of Technology, Gazi University, 06500, Ankara, Turkey
² Department of Physics, Faculty of Science, Gazi University, 06500, Ankara, Turkey
³ Department of Mechanical Engineering, Faculty of Engineering, Gazi University, 06570, Ankara, Turkey

^a erdem.mermer@gazi.edu.tr

Received: 17 November 2021
Accepted: 5 May 2022
Published online: 17 May 2022

Abstract

In this work, structural, elastic and mechanical properties of Hf-doped TiAl₂ and α-TiAl₃ alloys up to 4 wt. % in increments of 0.5 wt. % have been investigated by first-principle calculations within density functional theory for the first time. The structural models have been established using the virtual crystal approximation (VCA) method. Theoretical calculations indicate that calculated lattice constants agree well with previous studies. The formation energies of the alloys having more than 2 wt.% Hf concentration are lower than pure TiAl₂ and α-TiAl₃ alloys. Obtained elastic constants and elastic values indicate that Hf doping improves mechanical properties. Ductility has been improved when Hf addition is greater than 2.5 wt. % for α-TiAl₃ alloy and 3.5 wt. % for TiAl₂ alloys as compared to the pure states of these alloys. Further, the machinability index has been calculated.