Thermal Behavior of Frictional Properties on Ultra-Thin Perfluoropolyether Lubricant Film

Abstract

We investigate the thermal behavior of the friction property of ultra-thin perfluoropolyether (PFPE) lubricant film on diamond-like carbon (DLC) overcoats of magnetic disks. We use a newly developed pin-on-disk tester with laser irradiation heating. Results show that the friction coefficient of a lubricated DLC surface with Z-tetraol decreased with increased temperature, while for lubricated disks with Z-03, it gradually decreased at around 120°C and increased over 120°C. This minimal point may indicate the transition temperature. The friction coefficient of both lubricant films on the DLC surface varied with the kinematic viscosity of the lubricant materials, and decreasing the kinematic viscosity decreased the friction coefficient.

Keywords

• hard disk drive
• head disk interface
• heat-assisted magnetic recording
• perfluoropolyether