Influence of surface texture of a thin-film rigid disk on frictional properties at the head-disk interface

Contact start/stop tests (CSS) on thin-film rigid disks were carried out with reference to the surface texturization. Frictional properties at the head/disk interface in the middle of the CSS tests are correlated with the statistical characteristics of surface profile data. The data-processing techniques and the successful evaluation method for the surface texture are presented. It is demonstrated that the height distribution of asperity peaks selected by rolling a circle is able to distinguish subtle discrepancies among textured disk surfaces. The coefficient of friction between a head and a disk is not always dependent upon the mean roughness value of a disk surface, but also upon the height distribution of selected peaks and the liquid lubricant. Without liquid lubrication, the textured disk with a flatter distribution of selected peak heights provides good head/disk-interface durability. Additional liquid lubricant tends to increase the friction force, particularly for the disk with uniformly distributed peaks at the same time.<
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