Electro Polishing

Electro polishing slightly dissolves the surface of parts to improve surface finish by 2X, remove small feather burrs, reduce friction and/or creating a clean, uniform, bright-looking appearance.

MicroGroup’s electro polishing process can control stock removal tightly to achieve close dimensional tolerances.

Electro polishing increases the ratio of chromium-to-iron by removing free ions from the surface, therefore leaving it in a passive state (passivation). The passive surface consists of chromium oxides that improve its corrosion resistance.

Electro polishing is performed in an electrically controlled tank. The parts are submerged into a formulated acid bath, into which a D.C. current is applied. The quantity of material removed is directly proportional to the amount of electrical current and time applied.

MicroGroup builds custom electro polish racks to ensure consistent processing of components as well as ideal placement of the intrinsic rack mark. Electro polishing typically improves the surface finish by half, so a 16µin finish may improve to about an 8µin. The process produces parts that are noticeably shinier, and with greater passivation than chemical passivation processes can produce. In addition to exterior part surfaces, MicroGroup can electro polish interior surfaces, within limits determined by the engineering staff.