Additive manufacturing enables complex lightweight aluminium components but often generates microvoids or microcracks degrading the mechanical properties. Introducing healing ability into high-strength Al alloys could mitigate these defects and improve structural integrity. A new high-strength and healable Al-Mg-Zr alloy, Almazium®, was developed and processed by Powder Bed Fusion - Laser Beam/Metals (PBF-LB/M). High Mg content and Zr-induced grain refinement produce a fine bimodal microstructure and a yield strength of 317 MPa in the as-built condition. Synchrotron X-ray nano-holo-tomography revealed that a Healing Heat Treatment (HHT) at 540 °C for 30 min fully closed 65% of submicrometric voids, with complete healing up to 3.7 µm. At 400 °C, 90% of submicrometric voids were fully healed, with a maximum healed size of 1.5 µm. Scanning Transmission Electron Microscopy and Atom Probe Tomography revealed a high Mg content in solid solution, supporting a Mg diffusion-based healing mechanism. The healing behaviour was maintained after a second thermal cycle, confirming the alloy’s re-healability. Under combined heat and pressure, the healing efficiency increased drastically, allowing full closure of voids up to at least 100 µm. These findings demonstrate that Almazium® combines high mechanical strength with intrinsic, replicable healing ability.
De Raedemacker, S., Gheysen, J., Hannard, F., Villanova, J., Mottay, W., Tingaud, D., Winiarski, B., Ahmadi, M., Hoummada, K., Farag, M., Attallah, M. M., Idrissi, H., & Simar, A. (2026). Development of a new high-strength diffusion-assisted healable Al-Mg-Zr alloy produced by Powder Bed Fusion - Laser Beam/Metals. Materials & Design, 268, 116546. https://doi.org/10.1016/j.matdes.2026.116546 (Original work published 2026)