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Published January 5, 2025 | Published
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Magnetic response and hardness enhancement by spontaneous directional coarsening of Fe₂AlB₂ in quasicrystal-rich matrix

Bardziński, Piotr Józef1, 2 ORCID icon
Weselski, Marek1 ORCID icon
Asimow, Paul D.3 ORCID icon
Hu, Jinping3 ORCID icon
Fu, Roger Rennan4
  • 1. ROR icon University of Wrocław
  • 2. ROR icon Wrocław University of Science and Technology
  • 3. ROR icon California Institute of Technology
  • 4. ROR icon Harvard University
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Abstract

This study investigates the Al55Cu20Fe15B10 alloy system to understand the characteristics of the Fe2AlB2 (Cmmm) phase and its interactions with a quasicrystal-rich matrix. The alloy's composition was chosen for its boron content, which promotes the formation of well-defined Fe2AlB2 crystals. We examined how different heat treatments affect the alloy's microstructure, magnetic properties and hardness. Microstructural and Electron Backscatter Diffraction analyses revealed the stable icosahedral Al59Cu27Fe12B2 quasicrystalline phase and a metastable Al70Fe20Cu10 approximant that is isostructural with C2/m Fe4Al13. Additionally, the alloy contained Al-Cu phases known from meteorites, such as AlCu stolperite and Al2Cu khatyrkite. Heat treatments at 706∘C and 828∘C yielded favorable microstructure for ballistic armor, characterized by Fe2AlB2 lamellae embedded within the quasicrystalline matrix, reinforced by AlB2 precipitation on the grain boundaries. Vickers hardness improvements were attributed to Hall-Petch strengthening and grain orientation effects. Notably, annealing at 943∘C nearly tripled the magnetic entropy change. Quantum Diamond Microscopy confirmed that Fe2AlB2 significantly contributed to magnetization. The improvement of magnetic properties was found to be due to preferential orientation of Fe2AlB2 grains along the [010] zone axis, as a consequence of directional coarsening induced by annealing. The enhanced magnetocaloric properties observed at 943∘C are primarily due to intrinsic changes in the Fe2AlB2 phase rather than strain relaxation or phase contributions from the quasicrystalline matrix.

Copyright and License

© 2024 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Acknowledgement

The research described was funded by the National Science Centre, Poland (NCN) research grant No. 2018/02/X/ST5/02997 (synthesis and thermal treatment) as well as National Science Centre, Poland (NCN) research grant No. 2020/36/C/ST5/00007 (magnetic properties, microstructure, structural measurements, data processing). Hardness tests were performed from the corresponding author’s private funds. EBSD analyses were carried out at the Caltech GPS Division Analytical Facility, which is supported, in part, by NSF Grants EAR-0318518 and DMR-0080065. NV ODMR analyses were performed at the Department of Earth and Planetary Sciences, Harvard University, USA.

Data Availability

The source data are available under the CC-BY license in the Re-pOD repository (https://doi.org/10.18150/B3IEDV). The data will be available to the general public after embargo period: 14.12.2024.

Contributions

Piotr Józef Bardziński: Writing – original draft, Visualization, Supervision, Project administration, Methodology, Investigation, Funding acquisition, Data curation, Conceptualization. Marek Weselski: Resources, Investigation. Paul D. Asimow: Writing – review & editing, Validation, Supervision, Resources. Jinping Hu: Writing – review & editing, Validation, Investigation. Roger Rennan Fu: Writing – review & editing, Resources, Investigation.

Additional details

Related works Dates Caltech Custom Metadata
Created:
February 20, 2025
Modified:
February 20, 2025