Publication detail

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

Abdoshahi N. Dehghani M. Ruban A.V. Friák M. Šob M. Spitaler J. Holec D.

English title

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

Type

journal article in Web of Science

Language

en

Original 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 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 ti 12 at.%.(c) 2022 Published by Elsevier Ltd on behalf of Acta Materialia Inc.

English 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 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 ti 12 at.%.(c) 2022 Published by Elsevier Ltd on behalf of Acta Materialia Inc.

Keywords in English

Density functional theory; TiAl; Martensitic transformations; Diffusionless transformations

Released

01.02.2022

Publisher

PERGAMON-ELSEVIER SCIENCE LTD

Location

OXFORD

ISSN

1359-6454

Volume

240

Number

2022

Pages count

9

BIBTEX


@article{BUT182752,
  author="Martin {Friák} and Mojmír {Šob} and Neda {Abdoshahi} and Mohammad {Dehghani} and Andrei V. {Ruban} and David {Holec} and Juergen {Spitaler},
  title="On the energetics of the cubic-to-hexagonal transformations in TiAl plus Mo alloys",
  year="2022",
  volume="240",
  number="2022",
  month="February",
  publisher="PERGAMON-ELSEVIER SCIENCE LTD",
  address="OXFORD",
  issn="1359-6454"
}