On the energetics of the cubic‐to‐hexagonal transformations in TiAl+Mo alloys

0561578 - ÚFM 2023 RIV GB eng J - Článek v odborném periodiku
Abdoshahi, N. - Dehghani, M. - Ruban, A. V. - Friák, Martin - Šob, Mojmír - Spitaler, J. - Holec, D.
On the energetics of the cubic‐to‐hexagonal transformations in TiAl+Mo alloys.
Acta Materialia. Roč. 240, NOV (2022), č. článku 118268. ISSN 1359-6454. E-ISSN 1873-2453
Institucionální podpora: RVO:68081723
Klíčová slova: Density functional theory * TiAl * Martensitic transformations * Diffusionless transformations
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 9.4, rok: 2022
Způsob publikování: Open access
https://www.sciencedirect.com/science/article/pii/S1359645422006486?via%3Dihub

Diffusionless transformations allow access to metastable phases and enrich the materials design portfolio.
They are well suited for atomistic modeling, nonetheless, they are challenging when involving disordered
systems or alloys with complex compositions. This work presents a comprehensive study of transforma-
tion energetics between bcc and hcp ordered and disordered phases in the TiAl+Mo model alloy system.
By employing two complementary techniques I. VASP-SQS, and II. EMTO-CPA, we can show that chemical
disorder flattens the energy landscape but may introduce a small barrier. Unlike that, the energetics of
ordered phases are barrier-less and hence would suggest a spontaneous transformation. Finally, we show
that Mo stabilizes the bcc phases, leading to a barrier-less transformation hcp→bcc for both ordered and
disordered states when Mo content exceeds 12at.%.
Trvalý link: https://hdl.handle.net/11104/0334355