Slider/disk interface wear is inevitable for ultra-low flying hard disk drives and is the central issue for proximity recording. While disk wear has been addressed in the literature, slider wear has been largely considered to be trivial and is ignored. However, with the improvement of disk overcoat and introduction of diamond-like-carbon overcoat on slider air bearing surface, the surface hardnesses of the slider and disk are approaching each other and, therefore, the slider surface wear becomes significant or, in some conditions, even dominant. In this study, a theoretical model is developed for semi-steady-state slider/disk interface evolution of proximity recording which takes account of both the disk and slider wear. It includes the effects of the air bearing characteristics, pitch stiffness, material properties, and surface topography of both the slider and disk. Numerical results are illustrated for typical proximity recording interface, where the evolutions of the slider, disk, contact force, and pitch angle are evaluated for various air bearing stiffnesses, material properties, and surface topographies. This model is intended to provide some fundamental understanding of the slider/disk interface evolution during proximity recording process.
Dynamics of air bearing sliders flying on partially planarized bit patterned media in hard disk drives
