Sputtered carbon on particulate media

Abstract

The application of a thin, amorphous, carbon film to the surface of particulate magnetic media has been demonstrated as an alternative to liquid lubrication, eliminating the problems such as stiction, lube retention, and loss associated with traditional liquid lubricants. It also eliminates the necessity of nonmagnetic, load-bearing, alumina particles. The carbon has been deposited onto disks by DC magnetron sputtering from a graphite target. Extensive functional tests, including start/stop, stiction, accelerated wear, and pin-on-disk, have shown that carbon overcoat performs well on various types of particulate media and under a wide range of environmental conditions. The surface topography and chemistry of the particulate media uniquely enhance the tribological behavior of sputtered carbon on its surface, unlike ultrasmooth, thin-film magnetic media with carbon overcoat, which have been shown to be very sensitive to environmental conditions. >