Microporosity as key driver of the in-situ properties of a LPBF-AlSi10Mg mesoporous metamaterial

Metallic metamaterials are a novel class of metallic materials, which combine precisely-engineered mesoporous architectures with attractive properties of metals. When produced through additive manufacturing, they inherently contain defects whose influence on their tensile response is the main focus of this study. The effect of internal porosity on the elastoplastic matrix of AlSi10Mg mesoporous material response was probed in-situ, through a tensile test coupled with X-ray tomography and Digital Volume Correlation (DVC). By applying Integrated-DVC (I-DVC) with damaged meshes, the role of density defects (such as small pores and cracks within the matrix) on the strain hardening matrix parameters was quantified, and the identified properties were compared to bulk AlSi10Mg data reported in the literature. It is shown that density defects drove the in-situ matrix properties, highlighting the need to account for them when modeling the elastoplastic response of additivelymanufactured metamaterials. Simulations based on a defect-free matrix assumption yielded predictions that departed from the experiment.