Overall improvement of macro electrochemical jet milling by utilizing a novel cathode tool with an ultra narrow inter-electrode gap

Electrochemical jet milling (EJM) offers significant benefits for producing workpieces, showcasing various advantages in terms of quality and design flexibility. However, macro-scale EJM currently encounters limitations regarding machining efficiency and surface precision. A critical determinant of these aspects is the inter-electrode gap (IEG), with its optimization presenting an opportunity to enhance both precision and efficiency. Reducing the IEG is particularly desirable as it promises considerable improvements in machining efficiency and surface quality. Nonetheless, achieving a narrower IEG is challenging due to the risk of sparking from excessively high current densities at the cathode tool tips. To address this issue, this study introduces an innovative cathode tool design tailored to exploit the characteristics of electric in EJM. This design strategically removes the energy concentration area. As a result, this advancement allows for an ultra-narrow IEG of 0.05 mm, setting a new benchmark for the narrowest IEG achievable in macro EJM. Employing this novel cathode tool leads to a substantial leap in machining performance at an IEG of 0.05 mm. When compared with the conventional machining gap of 0.2 mm, the refined 0.05 mm IEG not only boosts the material removal rate by an impressive 107 % but also enhances surface quality. Specifically, the experimental results showed that the minimum surface roughness produced by the RD cathode tool was reduced by nearly 86.2 % than that of the surface produced by the standard cathode tool. Moreover, the overcut area was reduced by nearly 60.1 %, and stray corrosion was eliminated.