Systematic methodology to manufacture and validation of copper parts via material extrusion technology

Abstract

Material Extrusion for the realization of metals parts (MEX/M) is a multi-step Additive Manufacturing (AM) technology. Copper (Cu) for its intrinsic properties plays a critical role in application fields where it is requested to have high electrical and thermal conductivity. However, achieving high density and predictable shrinkage in MEX/M copper parts remains a significant challenge. This work systematically investigates the impact of layer height, flow rate and overlap percentage on the characteristics of the parts produced using a highly filled copper filament (87–90 wt.% copper and 10–13 wt.% PLA binder), following a Design of Experiments (DoE) approach. Green density, absence of defects, sintered density, pores distribution and shrinkage are the main drivers of the work. Furthermore, with the aim to validate the two most promising conditions identified from the DoE, comprehensive characterization is performed. Hardness and tensile tests assessed the mechanical properties, while Computed Tomography (CT scan) provided detailed insights into pore distribution and overall porosity. The current work contributes valuable understanding towards optimizing MEX/M process parameters to obtain free defects and dense copper parts with controlled dimensions, tailored properties and satisfying mechanical integrity.