Development of Metal Matrix Composites based on Al2618+ for Laser Powder Bed Fusion Additive Manufacturing

Abstract The demand for high-performance aluminum alloys in AM has surged due to their critical role in aerospace and high-temperature structural applications. However, the processability of high-strength Al-Cu-Mg alloys in LPBF remains a challenge due to their susceptibility to hot cracking, high thermal conductivity, and rapid solidification effects. This study investigates the development of advanced Al2618+ MMCs reinforced with TiC and TiB₂ nanoparticles to overcome these limitations and enhance the alloy’s mechanical and thermal performance. Al2618+, a Zr-modified derivative of Al2618, has shown promise for LPBF with improved densification and a refined microstructure. The introduction of Al₃Zr precipitates effectively mitigates hot cracking and refines grain morphology, yet further reinforcement is needed to optimize strength, wear resistance, and high-temperature stability. In this work, TiC and TiB₂ nanoparticles are integrated into Al2618+ via ball milling, acting as heterogeneous nucleation sites to promote grain refinement and suppress columnar growth. The introduction of the nanoparticles is expected to enhance mechanical properties through load transfer, Orowan, and Hall-Petch strengthening mechanisms, leading to improved hardness, wear resistance, and overall microstructural stability. A comprehensive characterization approach of the Al2618+/TiC and Al2618+/TiB2 composites is undertaken, including powder PXRD, SEM, and HRTEM to analyze phase stability, nanoparticle dispersion, and microstructural evolution. The powder’s flowability, morphology and rheological properties are also evaluated to ensure suitability for LPBF processing. To quantify the performance improvements, mechanical testing on printed samples will be conducted. This research advances the development of next-generation aluminum MMCs tailored for AM, paving the way for stronger, more reliable, and thermally stable components for aerospace and high-performance structural applications. Acknowledgements: This work has been carried out within the framework of the AM2C3 Horizon Europe Twinning Project funded by the European Union (101159727).