The effect of slider on lubricant loss and redistribution

The effect of the slider geometry and ABS on lubricant loss and redistribution has been studied by flying heads over disks with step-profile lubricant film. Two types of sliders, one with a negative pressure air bearing and truncated side-rails and the other with a positive air bearing, in the standard catamaran geometry, were used. The disks after flying were examined with a scanning reflectance analysis probe. After a short period of time, it was found that both sliders caused a comparable amount of lubricant depletion in the thick-film region. However, the redeposition in the thin-film region is seen prominently only under the slider with the negative pressure air-bearing. The result suggests that the lubricant depletion in one case results primarily from net lubricant loss or pickup, and in the other case from transfer and redeposition. Based on these results, a transfer mechanism under each slider type has been proposed. A discussion on the design implications is also included.