Infill Density Effects on the Mechanical and Thermal Properties of Copper-Plated 3D Printed Parts

Fused Filament Fabrication (FFF) is a 3D-printing technique that enables the production of complex geometries with a high level of customization at low cost. The poor mechanical properties of FFF-printed parts often undermine the application of this technology for structural purposes. To overcome this limitation, a two-step metallization method is performed to deposit a copper layer on the exterior of an Acrylonitrile–Butadiene–Styrene (ABS) substrate, using a non-toxic and cost-effective plating solution. Electroplating over the exposed grid infill, at various densities, is exploited to improve the load transfer between copper and ABS. The resulting samples are characterized mechanically and thermally, and finite element modeling simulations are used to better understand the characterization results. It is found that an infill of 50–60% provides the best compromise between mechanical performance and thermal conductivity because the infill density is low enough to allow copper penetration into the material to create a strong mechanical interlocking with ABS, yet high enough to create multiple conductive bridges through the thickness of the sample. This study demonstrates the effectiveness of electroplating as a post-processing technique to simultaneously enhance the mechanical and thermal properties of FFF-printed parts and provides insights into the optimal design parameters for achieving this goal. © 2023 The Authors. Macromolecular Materials and Engineering published by Wiley-VCH GmbH.