When considering your options for finishing metal materials, one solution you might come across is passivation. Passivation is a process in which the free metal of a surface is eliminated, thereby increasing the surface’s resistance to corrosion. Although this does function to make the surface less chemically reactive, passivation is most effective when paired with a cleaning pre-treatment, such as pickling.
Being an older method of metal finishing, there are more efficient alternatives.
The Difference Between Passivation and Electropolishing
Electropolishing offers a less expensive, more efficient alternative to the traditional pickling-passivation combination. Often favored in the industries of food service and pharmaceuticals, electropolishing uses a temperature-controlled electrolyte bath to dissolve the surface layer of a metal. This removal creates a smooth finish that is non-stick, sterile, and easy to clean.
Electropolishing tends to be a faster and more flexible process that passivation. It also works to clean the workpiece as part of the process, eliminating the need for an extra pickling step.
The Benefits of Electropolishing
Electropolishing offers a number of benefits over traditional passivation. In addition to being more efficient, faster, and cheaper, it also is more readily applied to a wider range of metals. Take a look at our page on the benefits of electropolishing to find out more.
To learn more about passivation in chemistry take a look at the related Wikipedia page.