Characterization of the Macroscale Struts and Microscale Substructures in Ti–6Al–4V Octet-Truss Metamaterials

Metamaterials, characterized by repeated unit cells and typically processed through additive manufacturing, represent a departure from traditional solid materials, showcasing inherent hierarchical structures. This study systematically characterizes the multi-scale organization of Ti–6Al–4V octet-truss metamaterials. The unit cells and interconnected struts are observed at millimeter or macrometer scales, martensite plates at micrometer scale, and twinning or dislocations at the nanoscale. Through this topological- and metallurgical-integrated examination, the work illuminates the multi-scale structures inherent in metal metamaterials, offering insights into their intricate hierarchical composition.