The electrolytic production of an oxide layer on titanium and titanium alloys is done in accordance with the international standard for aerospace (Specification LN 29747).
In combination with lubricants, this layer serves to protect the titanium fasteners against wear and also provides limited protection for less precious metals against bimetallic corrosion if in contact with titanium. Because of the slight thickness of the layer (normally < 2µm) and the required etching preparatory treatment, which entails material abrasion in the same magnitude, it is not generally necessary to take alterations in dimensions into account. The producible colour range varies from blue shades of various intensity and vividness, including yellowish, reddish and greenish colours up to violet.
Apart from applications in aviation and space travel, it is also used in orthopaedics and medical technology.