The electropolishing process is well-suited for deburring. During the process, the transfer of metal ions occurs most rapidly on corners or edges of metal parts. Current density or concentration of electrochemical power is greatest at high points, just as lightning is drawn to tall trees and buildings. This helps explain why plating builds metal faster on an edge or burr, while electropolishing (the “reverse” of plating) removes metal fastest at these points.
Differences in Deburring Methods
Properly controlled, the electropolishing process can remove burrs from incredibly complex or fragile parts that do not lend themselves to conventional tumbling or vibratory finishing techniques. The process is best suited for parts having fine blanking, milling, broaching, lapping or grinding burrs. Since electropolishing is non-mechanical, it is important to note that the hardness of a metal part has no bearing on the burr removal. The process works equally well on a fully annealed or hardened part. This is one reason why electropolishing is often specified as a final deburring and finishing process after all fabrication and heat treating processes.
The fact that electropolishing is a non-distorting process is often overlooked. Many metal parts produced today have critical microfinishes or are made from lighter, more fragile materials. In those cases, mass finishing techniques such as tumbling or vibra-finishing create distortion or warping, and can nick or scratch fine finishes. Electropolished parts are never subjected to stress from polishing media, nor are they impinged or tumbled onto each other.