Counter-rotating electrochemical machining of intensive cylindrical pillar array using an additive manufactured cathode tool

Pillar arrays on metallic surfaces gain important applications in industry, however the machining of them still remains great challenges for conventional methods. In this paper, counter-rotating electrochemical machining (CRECM) using a small cathode tool with multiple hollow windows was proposed to fabricate intensive cylindrical pillar array on revolving surface. The cathode tool was designed on basis of the anode shaping process in CRECM. The results indicated that in order to obtain desired circular pillar structures, the hollow windows on the cathode tool should be designed to be non-circular shapes and their sidewalls needed to be electrically insulated. These multiple specific-designed hollow windows bring challenges for conventional methods. To machine the specific-designed cathode tool, a novel hybrid additive manufacturing process combining 3D printing and electrodeposition was presented. A cylindrical cathode tool with multiple non-circular insulating hollow windows was successfully fabricated through electrodeposition on a 3D printed base part with partial conducive treatment. CRECM experiment of intensive pillar array was conducted using the additive manufactured cathode tool. An intensive (60 x 7) cylindrical pillar array with average dimensions of 4.3 mm diameter and 2.4 mm height was machined on the revolving surface. The profiles of different pillar structures exhibited favorable uniformity.