Experimental study on solid dielectric electrochemical polishing for high-roughness metal additive manufacturing surfaces

Surface quality remains a critical challenge for metal additive manufacturing (MAM) parts. Solid dielectric electrochemical polishing (SDECP) shows potential for polishing MAM components with high roughness and complex geometries; however, the effects and interactions of its process parameters have not yet been clarified. In this study, we employ design of experiments (DOE) methods, including the Taguchi method (TM) and response surface methodology (RSM), to investigate the effects of key parameters such as electrolyte composition, voltage, duty cycle, and anode movement speed. The main effects and interactions of these factors on surface roughness reduction performance in SDECP are analyzed using analysis of variance (ANOVA), signal-to-noise (S/N) ratios, main effects plots, response surfaces, and contour plots. Three-dimensional profiles and micromorphology of SDECP-treated surfaces reveal that pores formed during the MAM process are critical factors affecting surface quality. A regression model is developed to clarify the relationship between SDECP parameters and the surface roughness reduction rate of MAM surfaces. This model is then used to optimize parameter combinations, with its effectiveness confirmed by experimental validation. This work provides an optimized set of parameters for SDECP and offers valuable insights into the surface post-processing of MAM parts with high initial roughness.