Laser powder bed fusion of bio-inspired rotational lattice metamaterial with advanced mechanical performance

Abstract

Inspired by the helicoidal micro-architecture of mantis shrimp's telson, we propose a design concept for mechanical metamaterials based on the integration of rotational configuration and Octet lattice structure to enhance the mechanical performance of lattice metamaterials. The rotational Octet lattice (R-Octet) metamaterials are manufactured using the laser powder bed fusion (LPBF) process with NiTi alloy. The forming quality is analyzed through the micro-CT method, and the mechanical properties are investigated by combining compressive experiments and finite element simulations. The micro-CT results show that the R-Octet has high dimensional accuracy (peak deviation is 1.28 μm) and high relative density (>99%). Compared with the Octet lattice, the R-Octet metamaterials exhibit a higher Young's modulus and specific energy absorption (SEA) ability. The SEA of R-Octet with a twist angle of 15° is improved by 22% compared with that of the Octet lattice. Based on the experimental and simulated compression, it is found that the incorporation of the twist angle effectively eliminates the shear bands of the Octet lattice and provides a more homogeneous stress distribution in R-Octet, leading to a shift in the deformation mode from the layer-by-layer buckling of Octet to the global buckling of R-Octet. Moreover, the effects of twist angle on the mechanical performance of R-Octet are further explored to identify the optimal R-Octet. This work demonstrates the effectiveness of a bio-inspired rotation design strategy in high-performance lattice metamaterials and expands the boundaries of lightweight metallic materials.

Keywords

• Bio-inspired
• Lattice metamaterials
• Additive manufacturing
• Laser powder bed fusion
• Mechanical properties