Electropolishing is a process where a metal substrate (often steel, aluminium or titanium, but also a wide range of other metals and alloys) is immersed in an acid containing ionic solution (electrolyte) and an anodic electrical current is imposed onto it. This invokes a controlled corrosion process, effectively removing surface irregularities, such as sharp edges caused by scratches and hair-line surface cracks.

In a certain way, electropolishing is related to electrochemical machining, with the important difference that in electropolishing there is no significant shape change. For example, a process "electrochemical deburring" is somewhere on the edge between ECM and electropolishing (hence merely a matter of definition). Typically, electropolishing removes only a few microns of material.

Electropolished surfaces are stress-free and smooth, significantly prolounging the life time of the processed device or object. Often electropolished surfaces also have a mirrored appearance. The process also improves adhesion through the removal of oils and oxides, yielding a clean surface for any subsequent production step.

The product application range is huge, including surgical devices (e.g. stents, needles), nuclear accelerators, sensors, valves, storage tanks etc.

Controlling the current density distribution (hence effectiveness of the process) over the substrate is a major challenge for most electropolishing processes. This might require improved cell design, including screens, auxiliary cathodes and/or current thieves. Optimizing an electropolishing tank design can be performed in a very fast and effective way using relevant Elsyca simulation tools Elsyca PlatingMaster and Elsy2D.