Laser powder bed fusion of nano-CaB6 decorated 2024 aluminum alloy

Philipp Mair, Valerie Sue Goettgens, Tobias Rainer, Nikolaus Weinberger, Ilse Letofsky-Papst, Stefan Mitsche, Gerhard Leichtfried

Research output: Contribution to journalArticlepeer-review


The 2024 aluminum alloy (Al-Cu-Mg) is widely used in aerospace; however, due to its solidification-cracking tendency, its processability using laser powder bed fusion (LPBF) remains a critical issue. The addition of 2 wt% CaB 6 nanoparticles induces a columnar-to-equiaxed transition (CET), resulting in an immediate improvement in LPBF processability. High-density (>99.5%) and crack-free specimens, with a homogeneous equiaxed microstructure and without preferred grain orientation, were obtained. The small average α-Al grain size of 0.91 ± 0.32 µm is attributed to the similar lattice constants of Al and CaB 6 facilitating Al nucleation on CaB 6 nanoparticles, resulting in a highly coherent Al/CaB 6 interface. CaB 6 nanoparticles act as heterogeneous nucleus and exert a pinning force on the grain boundaries, which reduces grain coarsening. The as-built specimens exhibit both high-yield strength (348 ± 16 MPa) and high-tensile strength (391 ± 22 MPa), combined with a high total elongation at break (12.6 ± 0.6%). The macro hardness amounts to 132 ± 4 HV 5.

Original languageEnglish
Article number158714
Number of pages10
JournalJournal of Alloys and Compounds
Publication statusPublished - 2021


  • 2024 aluminum
  • Additive manufacturing
  • Alloy design
  • CaB
  • Laser powder bed fusion
  • Selective laser melting

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

Fields of Expertise

  • Advanced Materials Science

Treatment code (Nähere Zuordnung)

  • Basic - Fundamental (Grundlagenforschung)


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