Review—Electropolishing of Additive Manufactured Metal Parts

Abstract

Most metal additive manufacturing (AM) technologies are rapidly approaching, and in some cases even exceeding, the Technology Readiness Level 8, indicating that they are widely available and capable of completing a wide range of projects despite identified process restrictions. Thanks to significant technological progress made in the last decade, more industries are incorporating metal AM in their production processes to obtain highly customized parts with complex geometries. However, the poor surface finish of AM parts is a major drawback to their aesthetics and functionality. Over the years, different approaches were proposed to enhance surface quality, each bearing its limitations. Among the proposed technologies, electropolishing is a strong candidate for improving the surface finish of AM parts. Here we review the literature on electropolishing of AM parts, and, to provide a comprehensive study of the different aspects involved, the origin and consequences of the surface properties of AM parts as well as an evaluation of other available post-treatment technologies. Finally, the existing challenges on the way and potential countermeasures to expedite the industrial application of the electropolishing process for post-treatment of AM parts as well as future research avenues are discussed.

Enhancing Surface Finish of Additively Manufactured 316L Stainless Steel with Pulse/Pulse Reverse Electropolishing

“…Previous work has shown that strain relief can be imparted by surface treatment, though this relief is derived from material properties (e.g., porosity, microstructure) which are controlled by the print parameters. 44 Electropolishing Methods EP studies were performed in a BioLogic flat cell reactor, shown in Fig. 3b, which allows the anodecathode distance to be consistently set at 6¢¢ (15.2 cm).…”

Comparative study of surface roughness between electropolishing process and traditional sanding for low carbon steel

“…Mechanical polishing, while effective in certain respects, often falls short in achieving the desired surface quality due to its tendency to ob-scure defects and induce compressive residual stresses. These residual stresses can weaken the material and make it more susceptible to corrosion and other environmental factors, thereby compromising the integrity and durability of metal components [1], [2]. In the early 20th century, significant advancements in surface finishing techniques were achieved through the discovery and development of electropolishing.…”

Electrochemical Polishing of Ti and Ti6Al4V Alloy in Non-Aqueous Solution of Sulfuric Acid

“…The surface layer formed during mechanical processing typically has a deformed structure and deviates from the core metal’s physicochemical properties, often negatively impacting corrosion resistance by increasing the surface electrochemical activity. Electropolishing eliminates this layer, resulting in significantly improved surface characteristics and properties [ 14 , 15 ]. This method does not cause mechanical interaction, damage, or residual stress [ 16 ].…”