Hybrid manufacturing of AlSi10Mg metamaterials: Process, static and impact response attributes

The work investigates the microstructural, static and impact mechanical attributes of hybrid-cast aluminum AlSi10Mg metamaterials. For the analysis, different metamaterial topologies, namely BCC, IWP and gyroid-based architectures, are considered. The microstructural characteristics of hybrid-cast metamaterials are thoroughly investigated, assessing their attributes through scanning electron microscopy (SEM) and CT-scanning methods. Moreover, their static and impact attributes are experimentally characterized, quantifying elastic and post-elastic properties, while associating the performance of hybrid-cast and as-built, powder bed fusion (PBF) based metamaterials. PBF samples yield overall superior Young's moduli and higher peak stresses, though upon a brittle post-elastic response. Contrariwise, hybrid-cast metamaterials result in a ductile post-elastic, continuum-type plastification performance with a considerable energy absorption capacity that depends on the metamaterial topology, aspects both experimentally and numerically elaborated. Under dynamic impact loading, substantial peak stress and toughness enhancement are recorded for the hybrid-cast specimens. The analysis furnishes process-structure-property benchmark data on the mechanical performance of advanced, hybrid-cast metamaterial topologies for the first time. We aspire that the provided results foster novel pathways in the engineering of advanced media for a variety of base materials beyond the aluminum alloy investigated here.