Additive Manufacturing of Nanoparticle-enhanced Aluminum Alloy 2024

Abstract

Laser Powder Bed Fusion (LPBF) of high-strength aluminum alloys such as AA2024 has long been challenged by hot cracking and poor thermal stability. In this study, we demonstrate that nanoparticle-enabled additive manufacturing using nano-treated AA2024 with nanoparticles (designated as 2024NT) effectively overcomes these limitations. By optimizing LPBF parameters and employing a chessboard scanning strategy, crack-free 2024NT samples with ultra-low porosity (<0.5%) were successfully fabricated. Compared with conventional wrought 2024-T4, the LPBF-processed 2024NT exhibits significantly refined microstructures, enhanced precipitation behavior, and superior mechanical performance. Specifically, the 2024NT-T4 alloy demonstrates a 34% increase in yield strength and a 17% improvement in ultimate tensile strength at room temperature, while maintaining moderate ductility. These improvements are discussed in terms of combined grain refinement and age-hardening, supported by literature showing that ceramic nanoparticle/dispersoid additions can promote finer strengthening microstructures and impede precipitates coarsening during thermal exposure. This work provides a viable pathway for enabling high-strength, thermally stable AA2024 components via additive manufacturing.