Novel high specific-strength multi-topology Al-Ni-Ti-Zr-Mn alloy using laser powder bed fusion additive manufacturing

Abstract

Additive manufacturing has opened a paradigm for the efficient and quick production of lightweight lattice structures showing characteristic high specific strength (strength-to-weight ratios). The current study describes the development of methodology and utilization of high strength Al alloy for building complex lattice using additive manufacturing. Thin plate lattice <1 mm of Al-Ni-Ti-Zr-Mn alloy with wide processing window, achieving an average yield strength of 63.13±3.32 MPa in compression, with 28 % lower density than Ti-6Al-4V demonstrates a successful design of Al-Ni-Ti-Zr-Mn alloys using laser beam powder bed fusion (PBF-LB). The mitigation of cracks within thin plate parallel to the loading axis was achieved through the formation of Al-Al₃Ni eutectic channels, exploiting the rapid solidification of this short-freezing-range alloy. In addition to multi-topology structural design, the enhanced strength is attributed to hierarchical microstructure featuring L1₂ phases, bimodal grain distribution, and solid solution strengthening by Mn. This work establishes a printability-performance synergy of Al-Ni-Ti-Zr-Mn alloy for thin plate complex lattice, advancing the use of metamaterials through PBF-LB.