The Influence of Lubrication on Head and Disk Wear

Magnetic disks are usually lubricated with fluorocarbon-type lubricants to reduce head and disk wear during the start/stop process of the disk rotation. In this paper, the influence of disk lubrication on the tribological characteristics of the head/disk interface is investigated by pin-on-disk wear tests and the head/disk friction tests.

The anti-wear performance of a lubricant is very high. For example, a lubricant coating of 8.4 × 10^?5 mg/cm² exhibits 1/20 of the ferrite pin wear rate of an unlubricated disk. For a lubricated disk, ferrite pin wear decreases at increased sliding velocities as high as 10 m/s, while pin wear increases rapidly with increased velocity for an unlubricated disk. The lubricant used here performs well in suppressing the wear increase caused by increased load. Regarding friction characteristics, however, an excessive amount of lubricant induces severe head/disk sticking, causing head crash. With respect to head/disk sticking, the upper-limit of the amount of lubricant is 8.4 × 10^?5 mg/cm².