Review—Principles and Applications of Electrochemical Polishing

Electrochemical machining (ECM) is an efficient and precise manufacturing technology with broad prospects for numerous applications. As a subset of electrochemical machining, electrochemical polishing (ECP) is an advanced surface finishing method that utilizes electrochemical principles to produce smooth and reflective surfaces on various materials, particularly metals. This process is distinguished by its ability to refine surfaces without causing scratches or other forms of mechanical damage, thereby providing a significant advantage over traditional mechanical polishing techniques. The high processing efficiency of ECP renders it particularly suitable for industries that demand large-scale production and high-quality surface finishes. This work reviews the fundamental aspects of ECP, comparing three mechanisms: viscous film theory, salt film theory, and enhanced oxidation–dissolution equilibrium theory. Furthermore, it examines the factors influencing the effectiveness of ECP, including electrolyte composition, temperature, electropolishing time, voltage, and current. Applications of ECP in stainless steel, copper, nickel, and tungsten are also explored, along with a summary of its integration with advanced technologies. Finally, perspectives on the future development of ECP are discussed.