Plasma electrolytic oxidation (PEO), also known as MAO (micro arc oxidation), is a surface technology process for anodic conversion coating formation in which the coating is primarily formed by complex thermochemical reactions in a gas-phase solid plasma.
The microporous, microstructured and chemically activated metal-ceramic PEO layers usually achieve a thickness of 10 to 200 μm and, due to a complex microstructure consisting of amorphous and nano- or microcrystalline phases of different substances, very high heterogeneous microhardnesses (from 100 HV to 2000 HV) and novel multifunctionality.
The fields of application range from highly wear-resistant and heat-resistant to high-quality decorative, thermally insulating or thermally conductive, electrically insulating or electrically conductive, light-reflecting or light-absorbing coatings on aluminum components and corrosion-protective coatings for magnesium to bioinert and bioactive coatings for medical titanium implants.
