Uniting high strength with large ductility in an additively manufactured fine-grained aluminum alloy

Actualizing the near net-shaping of lightweight aluminum (Al) alloys with both superior mechanical performance and complex geometry remains challenging. To address this issue, novel Al–Ti–C–B (TCB) master alloy powders were tailored as effective inoculators and introduced into the AlSi10Mg alloy powders to promote the heterogeneous nucleation of <i>α</i>-Al during powder bed fusion using laser beam (PBF-LB), leading to pronounced heterogeneous microstructure with bimodal fine-grains and improved distribution of eutectic Si. The modified alloy with a more refined and homogeneous microstructure exhibited an excellent strength–ductility combination due to microstructure modification, outperforming most previously reported commercial Al–Si alloys. We have developed an effective TCB grain refiner (inoculant) for PBF-LB of Al alloys, which can lead to the pronounced grain refinement and enhanced tensile strength and ductility.