Lubrication studies of head-disk interfaces in a controlled environment Part 2: Degradation mechanisms of perfluoropolyether lubricants

Abstract

The decomposition mechanisms of the perfluoropolyether (PFPE) lubricants were studied in this paper using several experimental approaches. The PFPE lubricant film can be bonded to disk surface by illuminating the lubricant film with ultraviolet (UV) light; then the durability of the head-disk interface can be improved. However, during the sliding process, the illumination with UV light can accelerate the decomposition of the lubricant, reducing the head-disk interface durability and causing more gaseous fragments because low-energy electrons created by the illumination interact with the lubricant molecules, activating and breaking up the molecules. A decomposition mechanism of the lubricant with the effect of low-energy electrons was proposed. Mechanical shear is also found to have an important effect on the decomposition of the lubricant. The partial pressures of the gaseous fragments of the lubricant increase rapidly with increase in the sliding velocity. No obvious effect of ambient temperature up to 70 °C on the decomposition of the PFPE lubricant was observed, although higher temperatures are expected to be detrimental.