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.

Blades are critical components of modern aero-engine. Among the many characteristic structures of the blade, the leading/trailing edges are key structures that have the greatest influence on the aerodynamic effect and power conversion of the blade. Electrochemical machining (ECM) is regarded as one of the most important techniques in blade manufacturing due to its process characteristics of high material removal rates, virtually no tool wear, and no areas of thermal or mechanical damage to the workpiece rim zones. Herein, an ECM method based on the four-directional synchronous feeding of four cathode tools is proposed to improve the machining accuracy of the leading and trailing edges of the blade. During blade ECM using this method, four cathode tools feed toward the basin/back surfaces and leading/trailing edges respectively. The dynamic processing simulation and flow field simulation results of the ECM process show that the proposed method eliminates the sharp changes in the electric field and electrolyte flow field at the leading and trailing edges seen in traditional machining methods. Thus, the electric field and flow field stability of the leading and trailing edges at the final stage of machining is greatly improved. Experimental comparison of the conventional and proposed ECM methods showed that four-directional synchronous feeding results in improved profile accuracy over repeated machining processes and good surface quality.

A metallic interconnect plate with a flow channel array is one of the most important elements in a solid oxide fuel cell (SOFC). Electrochemical machining (ECM) is considered to be an adoptable technology for fabricating flow channels in an interconnect plate on account of its efficiency and low cost. With respect to the traditional electrolyte flow mode in ECM cross-channel array, the electrolyte usually flows from one side to the opposite side of the rectangular processing area. However, obvious flow marks are typically formed at the bottom of channels perpendicular to the flow. According to multiphysical simulation analysis, the low electrolyte velocity in the channels perpendicular to the flow leads to uneven distribution of electrolyte products. To improve the uniformity of the flow field, two new electrolyte flow modes, “two-in and two-out” and “three-in and one-out”, are proposed. By adding one or two additional electrolyte inlets to the sides of the traditional flow field, the electrolyte flow velocity in the channels perpendicular to the traditional flow will be increased. Corresponding simulations and experiments were performed and the results showed that the “three-in and one-out” flow mode can produce a flatter bottom surface for the cross-channel array. Parameter optimization experiments for the preferred flow mode were undertaken and the optimal flow field parameters were determined.