ELECTROPOLISHED

Electropolishing is a surface treatment by which the metal to be polished acts as an anode in an electrolytic cell, dissolving itself. With the application of current, a polarized film is formed on the metal surface under treatment, allowing the metal ions to diffuse through the film. The micro and macro projections, or high points of the rough surface, as well as areas with burrs, are areas of higher current density than the rest of the surface, and dissolve at a higher speed, resulting in a smoother, more level and/or bevelled surface. Simultaneously, and under controlled conditions of current intensity and temperature, a polishing of the surface takes place.

In alloys, such as stainless steel, there is also the additional advantage that, since iron is a metal that dissolves easily, the content of chromium and nickel on the surface is increased, thus increasing resistance to corrosion.

En una escala macroscópica, el contorno de una superficie maquinada se puede considerar como una serie de picos y valles. La profundidad de los mismos y la distancia entre los picos dependen de los métodos utilizados para producir la superficie.

On a microscopic scale, the surface is even more complex, with small irregularities superimposed on the peaks and valleys.

In order to produce a truly smooth surface, both types of irregularities (macroscopic and microscopic) must be eliminated.

Thus, the functions of an ideal polishing process can be distinguished as

a) Smoothing: elimination of large scale irregularities (size greater than 1 micron)

b) Polishing: removal of small irregularities smaller than a few hundredths of a micron.