Revealing the (positive) role of porosity within polymeric additively manufactured lattices via X-ray computed tomography

The mechanical properties of lattice geometries are known to be significantly influenced by a variety of manufacturing defects. This study investigates the influence of porosity on the mechanical behaviour of strut-based body-centred cubic (BCC) lattice structures produced with powder bed fusion with laser beam PBF-LB/P using PA2200 nylon powder. The study combines advanced techniques, including in-situ laboratory X-ray computed tomography (XCT), synchrotron XCT to visualise pores and roughness in high resolution at a single-cell level and image-based finite element analysis (FEA). The findings show that failure in thin-walled AM lattices is governed by the combined effects of porosity morphology, location, surface roughness, and cross-section reduction. The presence of internal porosity is found to attenuate both the amplitude of elastic modulus fluctuations and the severity of stress concentrations induced by surface irregularities.