WEAR CHARACTERISTICS IN THIN-FILM MEDIA

This paper focuses on the influence of sublayer mechanical properties on tribological phenomena affecting thin-film media. To isolate the in fluence of individual sublayers, disks used in this investigation poss essed fewer layers than commercial media. Pin-on-disk experimentation was performed to investigate friction and wear of r.f.-sputtered carbo n deposited on two different substrates: an Al 5086 disk possessing a hard NiP coating, and a softer and more ductile Al 1100 disk. The C/Ni P disk had an apparent wear rate lower than the C/Al 1100 disk. The fr iction forces measured during testing were found to exhibit difference s in trend and magnitude. The C/Al 1100 disk produced mean friction cu rves which increased rapidly and subsequently levelled off. The fricti on curves of the C/NiP disk showed a tendency to increase slowly and s teadily throughout the test. During the early stages of the wear proce ss, the C/Al 1100 disk displayed substantial plastic deformation or pl oughing of the track region. Failure of the overcoat occurs through fr acture and delamination of the carbon film. During the wear process, t he C/NiP disk displayed evidence of adhesive wear. After a large numbe r of passes, abrasive wear became a significant contributing wear mech anism.