SUMMARY

Laser powder bed fusion (LPBF) additive manufacturing (AM) presents a unique opportunity to create geometries impossible to manufacture using traditional methods. Lattice structures, which utilize such a geometry, are favored for their high strength-to-weight ratios, gradable properties, energy absorption capacity, etc. However, due to their size, having features as small as 200 µm, lattice performance is detrimentally impacted by the surface texture, defects, and print heterogeneities characteristic of LPBF, which are inextricably linked to manufacturing parameters. While the impact of these defects is understood to be severe, the mechanisms of their creation, manufacturing and design strategies for mitigation, and effects on performance are either underdeveloped or not yet fully understood. To address this knowledge gap and, more broadly, manufacturability of lattices as it relates to structural performance, the proposed work will focus on three key objectives: (1) modeling strut-level process-structure-property relationships across a wide processing space, (2) exploring the structure-level process-performance relationships for lattice structures manufactured using varied laser parameters within this processing space, and (3) examining the effects and limitations of nodal fillets as a strengthening mechanism. This dissertation will provide a comprehensive understanding of the impacts of manufacturing parameters on lattice performance, ultimately providing methodologies and tools for optimization of lattice structure performance through manufacturing and design modification frameworks.