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

The decomposition mechanisms of the perfluoropolyether (PFPE) lubricants we re studied in this paper using several experimental approaches. The PFPE lu bricant film can be bonded to disk surface by illuminating the lubricant fi lm with ultraviolet (UV) light; then the durability of the head-disk interf ace can be improved. However, during the sliding process, the illumination with UV light can accelerate the decomposition of the lubricant, reducing t he head-disk interface durability and causing more gaseous fragments becaus e low-energy electrons created by the illumination interact with the lubric ant molecules, activating and breaking up the molecules. A decomposition me chanism of the lubricant with the effect of low-energy electrons was propos ed. Mechanical shear is also found to have an important effect on the decom position of the lubricant. The partial pressures of the gaseous fragments o f the lubricant increase rapidly with increase in the sliding velocity. No obvious effect of ambient temperature up to 70 degreesC on the decompositio n of the PFPE lubricant was observed, although higher temperatures are expe cted to be detrimental.