Black oxide coating

Black oxide coating is a controlled oxidation, where the material’s black corrosion product is produced on the surface. Black oxidation is a chemical process that runs in high temperatures. There are also methods for black oxidation in cold processes, but it does not give the same black color and characteristics. At Provexa we use high temperature black oxidation.

Black oxidation is used for different applications, such as decorative purposes, to prevent reflection or to lover the friction coefficient and the wear in a lubricated tribological contact. The layer thickness is thin, less than 1µm, which means that tolerances are not affected by the process. For corrosion protection oil is added afterwards.

Barrels are an example on a product which is often black oxidated, even though it often is called bluing for that application.

Black oxidation is a process that is most used on steel. But it is also possible to black oxidate stainless steel, copper, and brass. At Provexa we offer black oxidation on steel as well as on stainless steel, copper, and brass.