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MM: Fachverband Metall- und Materialphysik
MM 38: Mechanical Properties and Alloy Design: e.g. Light-Weight, High-Temperature, Multicomponent Materials III (joint session MM/KFM)
MM 38.5: Talk
Wednesday, March 20, 2024, 12:45–13:00, C 230
Effect of the V-VIB groups ternary elements on the properties of Ti2AlM-type O-phases: A first-principles study — •Zeinab Heidari Pebdani1,2, Florian Pyczak1,2, and Rebecca Janisch3 — 1Helmholtz-Zentrum Hereon, Geesthacht, Germany — 2BTU Cottbus-Senftenberg, Cottbus, Germany — 3ICAMS, Ruhr-Universität Bochum, Germany
Despite the recent introduction of γ-TiAl-based alloys into service, the assessment of TiAl-alloys based on the ternary Ti2AlM orthorhombic O-phase, which are promising high-temperature structural materials, has not yet been completed. The focus of this contribution is on the impact of ternary alloying elements of the V-VIB groups of the periodic table on phase stability, structural, mechanical, thermal properties, and lattice dynamics of Ti2AlM (M= V, Nb, Ta, Mo, W) type O-phases. All Ti2AlM compounds satisfy the Born stability criteria, but their properties are largely affected by the ternary element M. According to the energy of formation, Ti2AlMo is the most stable type of O-phase. The bonding behavior of all compounds is investigated by analyzing the electronic density of state plots. It was found that stronger Ti-M bonding enhances while stronger Ti-Al bonding decreases the ductility in the Ti2AlM compounds. The thermodynamic stability of the intermetallic phases is key information to further develop these materials. To consider this we have used a set of comprehensive ab initio methods, in order to determine the temperature dependence of the properties of those intermetallic phases.
Keywords: Intermetallics; Density Functional Theory (DFT); Titanium Aluminides; Orthorhombic phase; Mechanical Properties