Due to the fast disk rotation, the temperature distribution on the disk under laser illumination in heat-assisted magnetic recording (HAMR) tends to deviate significantly from an axisymmetric distribution. A lognormal approximation scheme for the temperature distribution containing a tail based on a fast-moving heat source solution was proposed for use in an equation for the lubricant film involving evaporation, surface tension, disjoining pressure and thin-film enhanced effective viscosity. The results reveal the process of formation of a lubricant trough: an indent of the lubricant profile first forms and grows to a steady-state depth, followed by a continuous extension at the rate of the disk velocity. Both evaporation and thermal capillarity due to the surface tension gradient contribute greatly to the creation of a trough in the lubricant profile while the latter also causes boundary ridges. Unlike the Gaussian temperature-based solution, the local minimum of the lubricant thickness occurs at the trailing edge of the thermal spot.
- Information Storage and Processing Systems Division
Lubricant Evaporation and Flow due to Laser Heating With a Skewed Temperature Distribution Induced by Disk Motion
Haq, MA, & Wang, S. "Lubricant Evaporation and Flow due to Laser Heating With a Skewed Temperature Distribution Induced by Disk Motion." Proceedings of the ASME 2017 Conference on Information Storage and Processing Systems collocated with the ASME 2017 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. ASME 2017 Conference on Information Storage and Processing Systems. San Francisco, California, USA. August 29–30, 2017. V001T01A019. ASME. https://doi.org/10.1115/ISPS2017-5477
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