Elastic contact mechanics-based contact and flash temperature analysis of impact-induced head disk interface damage

Shock-induced impulsive slider-disk contact during operation poses a major challenge for modern hard disk drives (HDD). The high contact pressure and surface temperature that are usually associated with such impact could lead to the loss of data or even catastrophic failure of the head-disk interface, rendering the HDD inoperable. In this work, an elastic contact mechanics-based analysis was performed to investigate the impact between a slider corner and a disk surface. First, the analysis uses a homogeneous, smooth contact based on Hertzian impact theory, and trends of critical contact parameters were discussed for various combinations of impact velocities and slider corner radii. From these results, disk plastic failure was identified based on the mean contact pressure. Then, a similar approach was adopted to extend the impact analysis to consider the effects of mechanical properties and thickness of various layers, adhesion, and roughness on the severity of slider-disk impact. Lastly, flash temperatures during the impact were calculated for various conditions, and it was found that thermal erasure could occur under current head-disk impact conditions.