Feasibility of 3D-printed polymeric covers for electrode wires in electropolishing of additively manufactured parts with internal channels

This work discloses the preliminary results of a feasibility study of a novel setup and procedure for electropolishing internal channels of additively manufactured components. A specially designed and printed polymeric cover was assembled with a flexible stainless steel 316 wire to facilitate electropolishing of internal channels with various curvatures. Experimental studies were conducted to assess the feasibility of the process. The presence of curvatures was found to influence the formation and removal of conductive solid reaction products, thus affecting the electropolishing performance accordingly. A maximum surface roughness Sa reduction from 10.86 ± 0.50 μm to 1.44 ± 0.46 μm was obtained for straight channels after electropolishing for 20 min, while less efficient surface smoothening performance was observed on curved channels. Following that, a numerical simulation was conducted for optimization of wire covers, and the performance of three designs were analyzed and compared. While challenges need to be solved for improving the electropolishing performance and reducing the limit of the channel size that can be electropolished, the methods show significant potential on electropolishing curved internal channels, which can be further used in industrial-scale applications.