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Abstract
The head/medium spacing in magnetic tape and disk storage systems continues to decrease in the effort to increase areal recording density. Contacts between the head and the medium cause wear and limit data reliability. The tribology of the head-tape and head-disk interface has to be well understood in order to optimize the choice of head materials, head contours and overcoat materials for low friction and wear.
The micro-indentation method was applied to measure the wear of tape heads in drive level tests and to study the effect of hardness on wear durability. The nanohardness and nanoscratch resistance of head materials was compared with their wear resistance in the actual head-tape interface. The apparent inconsistency between wear durability and nanohardness could be explained by considering the microstructure of the head materials.
The phenomenon of stain formation and wear of helical scan tape heads was investigated as a function of relative humidity. The chemical composition and origin of stain on video heads was also studied using electron microscopy and Auger spectroscopy. The stain was attributed to wear debris originating from the magnetic tape.
The nanoindentation technique was applied to measure the hardness of diamond like carbon coatings on magnetic recording sliders. Atomic force microscopy and Raman spectroscopy were applied to measure the nanowear of diamond like carbon coated magnetic recording sliders. Good agreement was obtained for wear measurements using these two techniques. The effect of nanomechanical properties on the wear durability of sliders in spinstand tests was investigated.
The wear of proximity recording sliders was measured as a function of the air bearing stiffness, sliding distance, and interference between the slider and the disk. Higher air bearing stiffness resulted in larger wear of sliders. The dynamics of proximity recording sliders was investigated using laser Doppler vibrometry and acoustic emission analysis. The glide characteristic of the disks was found to depend on the lubricant thickness.
