Study of Contact-Action of a Positive-Pressure Step-Slider at Low Flying-Height.

Abstract

We studied the contact characteristics of a positive-pressure step-slider flying over a thin-film disk under two conditions : rotating at a low velocity at normal pressure (LV condition) and rotating at normal velocity at low pressure (LP condition). Drag test revealed head wear on the leading pads of the step-slider tested under the LP condition, while there was no change on the pads of the slider tested under the LV condition. To find the cause of this head wear, we measured acoustic emission (AE) signal, friction force, and head flying characteristics under both conditions. It was thus, (1) that the friction force between the slider and the disk is larger under the LP condition than under the LV condition, and, (2) that the contact angle between the slider and the disk is larger under the LV condition than that under the LP condition. And we think that the low contact angle under the LP condition makes the leading pads contact the disk and, thus, cause the head wear. It is therefore concluded that the slider must fly in a steep attitude to achieve a low flying height.