Additively manufactured lightweight plate-lattice metamaterials with ultrahigh energy absorption

Additively manufactured plate-lattice metamaterials are promising for lightweight protective applications, but they often suffer from high initial peak stress and low specific energy absorption (SEA). Here, we introduce a novel metamaterial design concept based on arched open-cell plates to overcome these limitations. Two architectures—Arch-BCC and Arch-FCC—were designed by placing arched plates on crystallographic-inspired (110) and (111) planes, respectively, followed by rotational patterning. The metamaterials were fabricated by laser powder bed fusion (L-PBF) using a Zr-modified 6061 Al alloy. Quasi-static compression tests and finite element simulations were performed to investigate their mechanical responses. The results show that both architectures exhibit customizable multi-stage stress plateaus, significantly reducing initial peak stress while enhancing energy absorption. Owing to segmented stress transmission, Arch-BCC achieves an exceptional SEA of 29.8 ± 1.2 J/g, and Arch-FCC reaches 23.7 ± 1.5 J/g, substantially surpassing most reported Al-based lattice metamaterials. This work provides a promising design route for high-performance, lightweight protective metamaterials for aerospace and automotive applications.