An “Electrolyte-Free” Electrochemical Polishing Method

Abstract Traditional electrochemical polishing (ECP) suffers from severe operational safety risks and environmental pollution hazards due to its reliance on highly corrosive acidic liquid electrolytes. As an alternative to traditional ECP, the quasi-solid ECP (QSECP) technology based on the solid polymer particle electrolyte system greatly reduces the usage of acidic liquid electrolytes. However, the polishing efficiency and performance of existing QSECP technologies still depend on the utilization of acidic liquid electrolytes. This work presents, for the first time, a novel “Electrolyte-Free” Electrochemical Polishing (EFECP) method that utilizes a resin particle-based quasi-solid electrolyte system to completely eliminate the use of traditional acid, alkali, or salt electrolytes, thereby showcasing remarkable advantages in safety and environmental friendliness. Furthermore, this polishing method demonstrated efficient polishing of hard alloy surfaces, which reduced the surface roughness of CoCrMo alloy sheets from 7.623 to 1.371 μm within 50 min. The polishing mechanism of EFECP has been comprehensively and in-depth studied, revealing a novel material removal mechanism based on “contact oxidation” combined with “collision removal” under neutral conditions, which differs from existing electrochemical polishing mechanisms. This work offers a revolutionary polishing technology for the metal surface treatment industry that is green, low-carbon, and holds broad application prospects.