ECM Study in a Closed-Cell System

The electrode reactions involved in electrochemical machining (ECM) of mild steel in NaC103 were studied in a closed cell system at constant current. The cathodic reaction is found to be essentially hydrogen evolution. At the anode, in addition to the metal removal, significant ~mounts of oxygen are produced and the total anodic current efficiency for Fe + + plus O2 formation is about 100%. Reduction of NaC103 to NaC1 during ECM is caused by the chemical reaction between NaC103 and Fe + +. The experimental results con-cerning the anodic process are qualitatively explained by the presence of porous anodic oxide films. Because of its unique method of removing metal, electrochemical machining (ECM) has found increas-ing industrial application in the last decade (1). For simplicity, ECM may be described as a controlled rapid anodic corrosion process. In the process, metal is re