Tribological rutile-TiO2 coating on aluminium alloy

The present paper describes a novel process developed to improve the tribological properties of aluminium alloys. The process involves the fabrication of a rutile-type TiO2 coating on an aluminium alloy by the combination of sputter-deposition of a pure titanium coating on the substrate and subsequent thermal oxidation. The resultant coating has a layered structure, comprising a rutile-TiO2 layer at the top, an oxygen and nitrogen dissolved a-Ti layer in the middle and a titanium–aluminide layer in the interfacial region. Such a hybrid coating system has good adhesion with the substrate, can significantly enhance the surface hardness and tribological properties of the aluminium alloy in terms of much reduced friction coefficient and increased wear resistance. # 2004 Elsevier B.V. All rights reserved