Abstract
In this work, crack-free samples with a relative density of 99.5 ± 0.1% were produced from a gas-atomized Al–Cu–Ag–Mg–Ti–TiB2 powder via laser powder-bed fusion. The homogeneous equiaxed microstructure without preferred grain orientation shows the α-Al grains’ mean size to be 0.64 μm ± 0.26 μm TiB2 particles with sizes of several tens of nm up to 1.5 μm were observed in the as-built component. Small TiB2 particles of up to approx. 200 nm are located within the α-Al grains, which show a semi-coherent interface to the α-Al phase. Larger TiB2 particles of up to 1.5 μm accumulate in the liquid between the growing α-Al grains during solidification and inhibit grain growth. Al2Cu phase is precipitated at the α-Al grain boundaries. Coarse Al2Cu precipitates, which are slightly enriched with silver and magnesium, are also observed within the grains preferentially precipitated on small pores and TiB2 particles. The novel fine-grained microstructure results in the as-built state in a tensile strength of 401 ± 2 MPa and total elongation at fracture of 17.7 ± 0.8%.
Original language | English |
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Article number | 140209 |
Journal | Materials Science and Engineering A |
Volume | 799 |
DOIs | |
Publication status | Published - 2 Jan 2021 |
Keywords
- Additive manufacturing
- High-strength aluminum alloys
- Laser powder-bed fusion
- Selective laser melting
- TiB
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering