Basing on an inert perforated metal mask, a hybrid electrochemical fabrication combining electroforming and mask electrochemical machining was proposed to manufacture metal through-hole array with double tapered openings. The feasibility of this novel process was investigated experimentally. The effects of pattern parameters of inert metal mask, such as wall angle, α, substrate thickness, H, hole spacing, L and hole size, D, on profiles of the resulting holes were analyzed. The experimental results show that the hybrid fabrication is able to manufacture high-aspect-ratio double tapered hole array with good surface quality.
Abstract
Aiming to solve the problems of the low electrolyte flow rate at leading edge and trailing edge and poor uniformity of the end clearance flow field during the electrochemical machining (ECM) of diffuser blades, a gap flow field simulation model was established by designing three liquid-increasing channels at the leading edge and the trailing edge of the cathode. The simulation results indicate that the liquid-increasing hole channel (LIHC) with an outlet area S of 1.5 mm2 and a distance L from channel center to edge point of 3.2 mm achieves optimal performance. In addition, the experiment results show that the optimized cathode with liquid-increasing hole channel (LIHC) significantly improves the machining efficiency, accuracy and surface quality. Specifically, the feed speed increased from 0.25 mm/min to 0.43 mm/min, the taper decreased from 4.02° to 2.45°, the surface roughness value of blade back reduced from 1.146 µm to 0.802 µm. Moreoever, the roughness of blade basin decreased from 0.961 µm to 0.708 µm, and the roughness of hub reduced from 0.179 µm to 0.119 µm. The results prove the effectiveness of the proposed method, and can be used for ECM of other complex structures with poor flow field uniformity.
Optimize the flow field during counter-rotating electrochemical machining of grid structures through an auxiliary internal fluid flow pattern