Measurement of flash temperature and contact between slider and magnetic recording disk

Flash temperatures and contact events were measured during tests of a low flying slider and rigid thin-film magnetic disks. The Al₂ O₃-TiC slider had iron-constantan thermocouples embedded in its rails. The thermocouples served as both temperature sensors and electrically conductive contact probes. The flash temperature was determined to be about 150°C during the impact of a single asperity and the slider. The impact load was found to be slightly less than 1 N. This value is slightly smaller than the force predicted by a theory based on slider inertia and indentation hardness. Contact event measurements disclosed that asperities on the disk surface deform plastically, even during the low-speed sliding encountered in contact start/stop cycles. The plastic deformation diminishes the severity of contact between head and disk in subsequent start/stop cycles