Mutifunctional arc ion plated TiO2 photocatalytic coatings with improved wear and corrosion protection

An arc ion plating (AIP) system was used to deposit anatase TiO2 thin films with photocatalytic and antimicrobial properties. This study aims to evaluate the properties and performance of such films, including surface hardness, adhesion, abrasive wear resistance and corrosion protection. The experimental results show that film hardness and scratch adhesion reach maximum values of 679.6 HV and 21.2 N, respectively. Film quality is strongly influenced by the degree of crystallinity, which is in turn affected by both deposition time and oxygen partial pressure. The wear resistance of the TiO2 coatings can be closely correlated to the film adhesion, however all films impart significantly higher resistance to abrasive wear than that of the uncoated surface. On the other hand, TiO2 coatings on stainless steel give rise to an increased (less negative) corrosion potential and decreased corrosion current in a sodium chloride solution. Overall, AIP-TiO2 film can however provide satisfactory protection for stainless steel.