Towards electroforming of copper net-shape parts on fused deposition modeling (FDM) printed mandrels

With the increasing demand for customization and personalization, the manufacturing industry faces new challenges related to cost-effective, low batch size production. Additive manufacturing (AM) is among the promising technology to address this problem. AM has however some limitations in metal structure fabrication, including high surface roughness, porosity, and poor mechanical properties. Electroforming on an AM mandrel could be a potential alternative solution for low batch production and complex structures with high aspect ratios. This process takes advantage of both high design freedom from AM and better structural control with electroforming. However, the uniformness, deposition quality, and end-geometry of the electrodeposition on a mandrel are not always guaranteed. In this paper, a method and an algorithm are proposed to improve the geometric precision of the deposition on the mandrel. The desired net-shape can be achieved by a corrected mandrel that takes the variable electrodeposition thickness into consideration. Therefore, the dimensional accuracy of the outer surface can be improved for applications requiring the dimensional accuracy of the outer shape, and a uniform part thickness is less important. In addition, a method that allows the forming of parts with controlled multiple thicknesses on the same mandrel is proposed. As one of the potential applications, the manufacturing of high-aspect-ratio flexures is demonstrated.