A comparative analysis of mechanical and surface properties of FCC lattice in FFF and MJF based additive manufacturing

Face Centre Cubic (FCC) lattices with varying porosities were designed and developed via Python scripting and printed using Fused Filament Fabrication (FFF) and Multi-Jet Fusion (MJF). The printed lattices were assessed through compressive tests and the compressive behaviour. Reverse engineering employing 3D scanning was utilised to evaluate the print quality and surface behaviour of the printed specimens. MJF-printed lattices exhibited fewer internal defects with superior surface quality and roughness compared to FFF samples. MJF also had higher compressive strength (~ 16 kN) than FFF samples (~ 10 kN) due to lower internal defects and closer bonding between the layers. The FCC lattices showcased an inverse relationship between porosity percentage and compressive strength with FFF and MJF lattices with 94% porosity outperformed structures with higher porosity in terms of compressive strength. Nonetheless, the deformation patterns in the lattices with 85% and 78% porosity resembled the 94% structure, indicating workable alternatives. Also, MJF-printed lattices with 78% porosity showed promise in simulating the mechanical characteristics of human tibial bones owing to closer match with human bones as well as their improved surface quality, deformability, and moderate compressive strength compared to other structures.