AAO coatings modified with copper using PVD and electrochemical methods

Abstract

The article presents the results of the initial research phase on modifying anodic aluminium oxide (AAO) coating with copper. AAO coatings were produced on the surface of the EN AW-5251 alloy, and copper plating was carried out using physical vapour deposition (PVD) technology and the electrochemical method. AAO-Cu coatings were examined microscopically to determine elemental composition and tribological and stereometric properties. Tribological tests were carried out on the T-17 stand in reciprocating motion with continuous and periodic lubrication. AAO-Cu coatings were combined with grey cast iron EN-GJL-250. The presented results show that the modification of the AAO coating with copper caused a reduction of the friction coefficient compared to the reference coating (AAO) by 55% (in the case of continuous lubrication) and by 34% (in the case of oil mist lubrication). The statistical analysis showed a significant dependence of coatings’ modification and lubrication method on their tribological properties. The research provides new information on coatings produced on aluminium alloys intended for use in sliding contacts in friction conditions with limited lubrication, which is undoubtedly a key issue in the era of continuous reduction of manufacturing costs.