The Effect of Disk Roughness on the Wear of Contact Recording Heads

Abstract

In conventional disk files, the slider is supported by an air-bearing when the disk is rotating at its designed speed. With the continued reduction of magnetic spacing in order to increase the areal density, a natural extension of the traditional recording system is contact recording. We investigate the wear of the contact recording head designed for such a class of rigid magnetic disk files where the read/write element carrying slider is intended to remain in continuous contact during every phase of the disk drive operation. In particular, we study the effect of disk roughness and load on the wear rate of the recording head. It is observed that the wear rate is proportional to initial interfacial load, however the observation cannot be extrapolated beyond the loads studied in the paper. The experimental observations agree well with expectations for a system where an abrasive wear model applies. We also show that the wear rate is predominantly governed by the existence of isolated asperities that lie well outside of three standard deviations of the disk surface roughness.