Microstructural evolution and phase stability in Nb-containing interstitial Fe-Mn-Co-Cr-C high-entropy alloys: An in-situ synchrotron X-ray diffraction study during laser melting
The influence of Nb on phase stability and microstructural evolution in an interstitial Fe-Mn-Co-Cr-C high-entropy alloy was investigated using in-situ synchrotron X-ray diffraction (SXRD) during laser melting. Scheil-Gulliver simulations predict the formation of σ and γ-f.c.c. phases in all three alloys, along with NbC in Nb-containing compositions. SXRD confirmed the presence of most predicted phases, but the σ phase was absent. Nb promotes crystallite refinement and increases dislocation density, though excessive additions reduce refinement efficiency due to solubility limits and secondary phase formation. Furthermore, Nb addition also enhances ε-h.c.p. phase formation by reducing stacking fault energy through NbC-induced carbon depletion. Analysis of intensity peak evolution reveals that Nb alters preferred grain orientations, reducing { 111 } γ intensity while enhancing { 220 } γ , leading to a more isotropic grain distribution. Overall, Nb plays a key role in phase selection, microstructure refinement, and preferred orientation evolution, allowing the tailored microstructure of high-entropy alloys via rapid solidification.
Authors
- Patrícia Freitas Rodrigues (ORCID: https://orcid.org/0000-0001-7616-6793)
- António B. Pereira (ORCID: https://orcid.org/0000-0001-8342-5116)
- Yutao T. Pei (ORCID: https://orcid.org/0000-0002-1817-2228)
- Giovani Gonçalves Ribamar (ORCID: https://orcid.org/0000-0001-8000-3081)
- Andrew Chihpin Chuang
- Wei Zhang (ORCID: https://orcid.org/0000-0001-6471-7412)
- Jiajia Shen (ORCID: https://orcid.org/0000-0001-8039-7690)
- Thiago Soares Nunes (ORCID: https://orcid.org/0000-0002-1323-8160)
- Isaque Alan de Brito Moura (ORCID: https://orcid.org/0000-0002-0024-6110)
- Fan Zhang (ORCID: https://orcid.org/0000-0001-9664-5177)
- J.P. Oliveira (ORCID: https://orcid.org/0000-0001-6906-1870)
Institutions
- Argonne National Laboratory (US)
- National Institute of Standards and Technology (US)
- University of Groningen (NL)
- Military Institute of Engineering (BR)
- Material Measurement Laboratory (US)
- University of Aveiro (PT)
- University of Coimbra (PT)
- Universidade Nova de Lisboa (PT)
Publication Details
- Journal
- Materialia
- Published
- 2025-08-04
- DOI
- https://doi.org/10.1016/j.mtla.2025.102512
- Citations
- 1
- Primary Topic
- High Entropy Alloys Studies
- Type
- article
- Field-Weighted Citation Impact
- 0.71
Funders
- U.S. Department of Energy
- European Commission
- Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
- Ministério da Ciência, Tecnologia e Ensino Superior
- Office of Science
- Fundação para a Ciência e a Tecnologia
- Argonne National Laboratory