Flow field design and experiment of high-efficiency electrochemical milling with large machining area

Materials that are difficult to cut, such as titanium alloys, are widely used in large load-bearing integral components of aircraft, leading to great challenges for manufacturing. Electrochemical milling is a way for machining difficult-to-cut materials through Computer Numerical Control (CNC) trajectory motion. Using a tilted large cathode machining surface and the cut-in feed mode, an efficient and low-cost method is obtained for machining the large integral components. A novel crossed and inclined structure of the flow mode is designed to realize electrochemical milling with a large tilted cathode surface. Compared to the vertical flow mode with one inlet, the proposed flow mode has two inlets that independently supply electrolytes, and the inclined channels make the flow field more stable. Flow field simulations are performed for both the vertical and proposed flow modes. The results show that the proposed flow mode avoids the random diversion of electrolytes and the ultralow flow velocity at both ends of the nozzle area, improving the velocity, uniformity, and stability of the electrolytes. The inclination angle of the crossed and inclined flow field is optimized. Finally, limit feed rate experiments are conducted in two modes, and the limit feed rate is 70 mm/min in the proposed mode. A sector workpiece of a large circular surface with approximately 8.77 mm thickness is machined 9 times by the cut-in electrochemical milling, the material removal rate is 4872 mm³/min, and the surface roughness is superior to 1.15 μm.