Abstract
A crack-free, strong and ductile Al-Cu-Mg-Ag alloy with TiB2 particles was successfully fabricated with laser powder bed fusion (L-PBF). Subsequent solution and aging were designed to modify the microstructure and strengthen the alloy. The as-fabricated alloy achieved an isotropic microstructure consisting of random-orientated and equiaxed grains with an average grain size of about 1.15 µm. The role of TiB2 particles in reducing metallurgical defects (such as hot cracking) and enhancing mechanical performance of the alloy was revealed by multi-scale advanced microstructural characterizations. This benefits from the formation of two-dimensional compounds of Al3Ti on the terminated (0001)TiB2 plane, which could reduce the lattice mismatch, alter the potency of TiB2 particles, and refine the grains. The as-built alloy shows an excellent combination of strength and ductility with a yield strength (YS) of 289 ± 5.7 MPa, ultimate tensile strength (UTS) of 390 ± 6.5 MPa, and elongation to failure (El) of 14.8 ± 1.8%. After the heat treatment, high-density of θ', Ω', and Ω phases were precipitated, significantly improving the YS to 405 ± 3.2 MPa and UTS to 470 ± 3.5 MPa, while slightly decreasing the El to 11.6 ± 0.9%. The strengthening mechanisms are quantitatively evaluated and the plastic instability phenomenon (Lüders band and Portevin-Le-Chatelier effect) of the as-built alloy was also analyzed.
Original language | English |
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Article number | 169311 |
Number of pages | 15 |
Journal | Journal of Alloys and Compounds |
Volume | 945 |
Early online date | 16 Feb 2023 |
DOIs | |
Publication status | Published - 5 Jun 2023 |
Bibliographical note
Funding Information:This work was supported by the National Natural Science Foundation of China [51771202, 51971225], Key Research Program of Frontier Sciences, CAS [QYZDY-SSW-JSC027], Basic and Applied Basic Research Program of Guangdong Province [2021B0301030003] and Ji Hua Laboratory [X210141TL210]. The authors also gratefully acknowledge Haiyang Jiang from the Institute of Metal Research, Chinese Academy of Sciences for assistance in SEM and EBSD characterizations.
Publisher Copyright:
© 2023 Elsevier B.V.
Keywords
- Grain refinement
- Laser powder bed fusion
- Mechanical property
- Microstructure
- TiB/Al-Cu-Mg-Ag alloy
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry