MECHANICAL AND TRIBOLOGICAL PERFORMANCE OF ION-BEAM DEPOSITED DIAMOND-LIKE CARBON ON POLYMERS

Ion-beam deposited diamond-like carbon (DLC) is an attractive coating material because of its combination of low friction, high hardness and chemical inertness. A nitrogen ion source is used, both to modify the substrate surface and to crack a low vapour pressure oil which is eva porated and condensed onto the substrate surface. Owing to the low dep osition temperature-components never exceed 80-degrees-C during the co ating process-and the ability to harden and densify the substrate surf ace in the same process, such DLC coatings are of particular importanc e for engineering polymers. In this study DLC coatings (approximately 1 mum thick) have been applied to a range of commercially, available p olymer substrates. Depositions have been carried out with and without surface modification of the polymer by ion bombardment prior to DLC co ating. The assessment of the mechanical properties of these coatings i s reported, including adhesion, wear resistance and fracture toughness .