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

Publikationen: Beitrag in FachzeitschriftArtikelForschung(peer-reviewed)

Autoren

  • Mohammed Dehghani
  • Andrei V. Ruban
  • Martin Friák
  • Mojmír Šob
  • J. Spitaler

Externe Organisationseinheiten

  • Materials Center Leoben Forschungs GmbH
  • Masaryk Universität
  • Königliche Technische Hochschule, Stockholm
  • Technische Universität Brünn
  • Czech Academy of Sciences, Brno

Abstract

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 transformation 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 hcpbcc for both ordered and disordered states when Mo content exceeds at.%.

Details

OriginalspracheEnglisch
Seiten (von - bis)118268
Seitenumfang9
FachzeitschriftActa materialia
Jahrgang240.2022
AusgabenummerNovember
DOIs
StatusElektronische Veröffentlichung vor Drucklegung. - 24 Aug. 2022