A new process combining micro-EDM-milling and micro-EDM-sinking for fast fabrication of micro-channels with draft angle.

A comparison of the machining performance of micro-EDM milling and sinking is proposed considering the fabrication of micro-channels with controlled sloped walls realized in a hardened steel workpiece. Adopting the fine-finishing machining regime for both micro-EDM techniques, the experimental results show that micro-EDM sinking is about 10 times faster than milling in the worst case, though a lack of accuracy in the final micro-features in the former case is detected due to not compensated tool wear. On the contrary, micro-EDM milling provides a better control of the micro-channel dimensions. Finally, a micro-filter mold for medical applications is machined in order to show the potential of the combination of both technologies.