Architected metallic cellular materials with random pore features: computer design, LPBF fabrication and mechanical properties

Abstract

Porous materials with heterogeneous pore features are used in many branches of technology, from lightweight structures to biomedical implants and electrodes. These materials derive their properties from their internal architecture, which is often poorly controlled via conventional manufacturing routes (e.g. foaming, templating). Here, we combine laser powder bed fusion (LPBF) additive manufacturing technology with computer design to fabricate metallic cellular architectures with heterogeneous, yet precisely controlled, pore features. The materials of this study contain through thickness pores - with arbitrary micrometric size and shape - randomly dispersed into a dense metallic matrix. Their porous architecture is generated numerically using a random sequential absorption algorithm, and is 3D-printed out of two metallic powders. Using image analysis, we statistically quantify the Influence of the LPBF process parameters on the 3D-printed pore geometry (i.e. morphology and size), and develop image-based finite-element models to measure numerically the resulting homogenized elastic mechanical properties. Collectively, our results help elucidate the role of geometric (i.e. topological) defects induced by the LPBF process on the structural performance of metallic cellular materials with random pore features.