Age hardenable Aluminum alloys renowned for its high strength and ductility, are increasingly used in additively manufactured lightweight components. Laser Powder Bed Fusion (LPBF) has enabled the fabrication of complex geometries in alloys with super-saturated solution due to rapid solidification. The as-built alloy is subjected to post-heat treatment to increase the strength, but the post-heat treatment is not optimized using a scientific approach. This leads to prolonged heat treatment time. In this study, a novel time-efficient heat treatment strategy for reducing thermal energy is investigated with regard to the sustainability of manufacturing processes using the example of an LPBF-manufactured AlSc alloy. Through an innovative simulation and experimentation-based approach, a cyclic heat treatment technique is derived, that promotes balanced nucleation and growth of strengthening Al3(ScZr) phases. Simulation models were used to predict the optimum volume fraction and density distribution of precipitates to maximize strength while retaining ductility. Then the cyclic heat treatment was derived based on the precipitation kinetics model to achieve the optimum volume fraction of precipitates. The phase transformation kinetics and experimental validation were conducted to confirm improvements in strength and ductility. The combination of simulations and real-world trials provides a reliable methodology for customizing heat treatments to meet specific performance requirements.

Keywords: LPBF, cyclic heat treatment, simulation, experimentation, sustainability, precipitation strengthening.