Formation and Removal Behavior of Oxide Film in Electrolytic In-process Dressing Superfinishing of Cylindrical Rollers
摘要
In electrolytic in-process dressing (ELID) superfinishing, the presence of oxide film contributes to a reduction in the surface roughness of the workpiece and mitigates material surface damage. Existing research indicates that the thickness, formation rate, and surface texture of the oxide film significantly affect the surface integrity of the workpiece. This paper proposes a novel method for ELID superfinishing of cylindrical rollers. The electrochemical reaction process of anodic dissolution is explained based on Faraday’s electrolysis theory. The contact state between abrasive and oxide film is analyzed using the principle of indentation fracture, revealing the wear removal process of the oxide film. A thickness prediction model based on the mechanisms of oxide film formation and removal is ultimately established. The validity of the model was verified through ELID superfinishing experiments on GCr15 bearing steel cylindrical rollers. After processing for 20 min under the selected conditions, the surface roughness Ra of the cylindrical roller from 167.2 nm to 18.5 nm, and the cylindricity from 3.609 μm to 2.884 μm. The study shows that the thickness and morphology of the oxide film are primarily influenced by the workpiece rotation speed, lapping force, and electrolyte voltage. The variation in oxide film thickness can lead to changes in the actual cutting edge height of the abrasive, thereby affecting the surface quality and shape accuracy of the machined surface.