Hu, Z., Gao, S., Mikula, J., Shen, X., Seet, H. L., Quek, S. S., Zhou, K., & Nai, S. M. L. (2024). Enhanced Plastic Stability: Achieving High Performance in a Al6xxx Alloy Fabricated by Additive Manufacturing. Advanced Materials. Portico. https://doi.org/10.1002/adma.202307825
Abstract:
AbstractAdditive manufacturing (AM) facilitates the creation of materials with unique microstructural features and distinctive phenomena as compared to conventional manufacturing methods. Among the various well‐fabricated AM alloys, aluminum alloys garner substantial attention due to their extensive applications in the automotive and aerospace industries. In this work, an Al6xxx alloy is successfully fabricated with outstanding performance. A nucleation agent is introduced to diminish the susceptibility to cracking during the AM process, thereby inducing a heterogeneous microstructure in this alloy. However, the introduction of ultrafine grains induces plastic instability, evidenced by the presence of Lüders band. This work investigates the evolution of the Lüders band and the strategy to reduce their undesirable effect. The heterogeneity destabilizes the band propagation and thus deteriorates the ductility. Through a T6 heat treatment, the local Lüders strain decreases from 10.0% to 6.2%, leading to a substantial enhancement in plastic stability. With the increase in grain growth and the enlargement of coarse grain regions, the mismatch between the local and macroscopic Lüders strain disappears. Importantly, the strength and the thermal conductivity are concurrently increased. The findings demonstrate the significance of ensuring plastic stability to achieve improved strength‐ductility trade‐off in AM alloys with heterogeneous microstructures.
License type:
Publisher Copyright
Funding Info:
This research / project is supported by the A*STAR - Structural and Metal Alloys Programme (SMAP)
Grant Reference no. : A18B1b0061
Description:
This is the peer reviewed version of the following article: Hu, Z., Gao, S., Mikula, J., Shen, X., Seet, H. L., Quek, S. S., Zhou, K., & Nai, S. M. L. (2024). Enhanced Plastic Stability: Achieving High Performance in a Al6xxx Alloy Fabricated by Additive Manufacturing. Advanced Materials. Portico. https://doi.org/10.1002/adma.202307825
, which has been published in final form at doi.org/10.1002/adma.202307825. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.