Influence of contact interface design over the bond for-mation of 3D printed parts

[EN] Fused Filament Fabrication (FFF) is an additive manufacturing technology that uses molten thermoplastic materials forced through a nozzle to build parts layer-wise and enables the manufacturing single and multiple materials parts. The multi-material interface bond strength influences the resulting part integrity. The interface represents the physical boundary between materials, and its shape depends on the part’s design. However, the most common interface designs are based on a flat surface-to-surface contact. Thus, this paper aimed to investigate if the interface strength of polylactic acid-based (PLA) parts can be enhanced by designing new interface geometries with a sinusoidal and zig-zag pattern orientated in two directions. The resulting interfaces were tested mechanically and analyzed under the microscope to describe bond formation. The results show that interface shape orientation and overlap between mating bodies significantly influence the multi-material interface strength.