Influence of FFF Substrate Material and 3D-Printed Surface Morphology on the Formation of Electrodeposited Copper Layers

Electrodeposition of metallic coatings represents a promising approach for extending the functional properties of additively manufactured polymer components. However, the resulting coating morphology may be influenced not only by the deposition conditions but also by the material and initial topography of the polymer substrate. In this study, the formation of electrodeposited copper (Cu) layers was investigated on Fused Filament Fabrication (FFF) substrates made of polylactic acid (PLA), PLA containing carbon fibres (PLA-CF), PLA containing brass particles (PLA-Brass), and polyethylene terephthalate glycol-modified (PETG), with different initial surface morphologies generated using three printing strategies. All samples received a conductive graphite interlayer and were subsequently electroplated under identical electrochemical conditions. The resulting Cu layers were characterised using cross-sectional observations and non-destructive 3D surface topography analysis. The results showed that the Cu coating retained the basic morphological character of the FFF substrate; however, its resulting topography was not a simple geometric replica of the original surface. Differences among the investigated materials and initial surface topographies remained evident despite identical deposition conditions. Cu layer formation was associated with changes in the peak and valley regions of the surface and local bridging of deeper depressions. The results demonstrate the importance of both substrate material and initial FFF surface topography in determining the resulting morphology of electrodeposited Cu coatings and indicate the potential of 3D surface topography analysis for non-destructive characterisation of Cu surface morphology.