Abstract
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 language | English |
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Article number | 158714 |
Number of pages | 10 |
Journal | Journal of Alloys and Compounds |
Volume | 863 |
DOIs | |
Publication status | Published - 2021 |
Keywords
- 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)