Lubricant replenishment on carbon coated discs

The replenishment of a lubricant on a carbon coated disc was characterized through theoretical modeling employing experimentally acquired diffusion coefficient data. To quantify the reflow behaviour of a lubricant film, a parameter, the critical reflow time, was defined as the time to replenish a depleted hole of 1 μm diameter in a 2 nm thick lubricant film. The results based on solving 2D diffusion equations showed that the critical reflow time is a strong function of the endgroup polarity and molecular weight of a lubricant, as well as the H and N content in the carbon film. Based on these results, design criteria have been provided for enhanced wear durability of magnetic media