TRIBOLOGICAL PROPERTIES OF COMPOSITE COATINGS ON ALUMINIUM ALLOY PARTS FOR TRANSPORT MEANS

Abstract

The present paper describes the structure, surface topography, and tribological properties of a DLC composite coating produced by magnetron sputtering on an engine cylinder liner AC-AlSi12NiCuMg (AC-47000) cast alloy as well as on AW-A6061 aluminium alloy matrix W6.A15A composite (AW-6061+10Al2O3P) used for the production of oil-less air compressor cylinders and car roof sliders. The DLC coating slid against a TG15 sliding composite under dry friction, which is an equivalent to the friction system for oil-less air compressors and against cast iron under limited lubrication conditions (boundary lubrication). The limited lubrication conditions are dominant during the starting of a cold combustion engine, when the viscosity of oil is too high and the splash lubrication is not sufficient. The DLC coatings’ properties are compared with the anodic hard coatings (AHC) and composite coating with an AHC matrix applied in sliding contacts presently used. The wear of composite TG15 during sliding against DLC was higher than during sliding against AHC. The DLC coating can replace the anodic hard coating and composite coatings on its matrix presently used in sliding contacts.