First-Principles Calculation for the Influence of C and O on the Mechanical Properties of γ-TiAl Alloy at High Temperature

Abstract

The elastic constants of temperature dependence, thermal expansion coefficient and phonon dispersion relations of γ-TiAl doped with C/O have been investigated using first-principles calculations in order to gain insight into the mechanical performance of γ-TiAl in cases of high temperature. This study shows that γ-TiAl maintains stability at high temperatures introduced by C or O atoms. Importantly, the hardness increases and retains excellent resistance to external pressure. The results indicate that even if the TiAl alloy is doped with C or O atoms, it can also exhibit excellent mechanical properties at a high temperature.

Electrons Meet Alloy Development: A γ‐TiAl‐Based Alloy Showcase

“…Finally, let us note that by combining the quasiharmonic approximation with the elasticity calculations, it is possible to use ab initio calculations to predict temperature‐dependent single‐crystalline elastic constants, as demonstrated, for example, by Wang et al [ 97 ] for several TiAl systems.…”

A New Method for Preparing Titanium Aluminium Alloy Powder

“…Metal compounds offer both the plasticity of metals, and the high-temperature strength of ceramics in specific compositions, due to the metal compound ordered arrangement of their atoms, and the coexistence of inter-atomic metal bonds and covalent bonds. TiAl-based intermetallic compounds were highly valued in the aerospace industry and other fields, due to their excellent mechanical properties and low density, in the 1950s [1,2]. Nowadays, the TiAl-based alloy is still recognized as a high-end material in the world [3,4].…”

Structural Change of TiAl Alloy under Uniaxial Tension and Compression in the <001> Direction: A Molecular Dynamics Study

“…Several experimental and theoretical studies on the mechanical properties of TiAl alloys have been published [21][22][23][24][25][26]. Tanaka et al [21,22] and He et al [23] experimentally measured the elastic constants of TiAl alloys at various temperatures.…”

“…They reported that these surface defects affect the strength of the TiAl alloy, where dislocations nucleate from edge defects and large surface defects [24]. Furthermore, Wang et al tested the elastic behavior of pure TiAl alloys [25] and C/O doping [26]. They found that C/O doping of TiAl alloys could increase the hardness of the material while retaining its resistance to external pressures [26].…”

“…Furthermore, Wang et al tested the elastic behavior of pure TiAl alloys [25] and C/O doping [26]. They found that C/O doping of TiAl alloys could increase the hardness of the material while retaining its resistance to external pressures [26]. However, to the best of our knowledge, no previous studies have reported changes in the structure of TiAl alloys at the atomic scale resulting from tensile and compressive loading.…”