Layer Moleculecular Dynamic Diffusion Model of Nano-Meter Lubricant Film on Hard Disk Surfaces at High Rotating Speed

Spin-off experiments for PFPE Z25 were conducted by using a 3.5 inch disk at a constant speed of 10,000 rpm. The initial film thickness was set to about 2.4 nm for all the experiments while temperature was changed in a wide range. It is found that the rheological behavior of the film is quite different from that expected from the continuum. A novel model based on Fick’s law of diffusion was proposed, which is called the layer molecular dynamic diffusion (LMDD) model. The theoretical prediction was compared with the experimental results and a good agreement was obtained, verifying the effectiveness of the model.Copyright © 2008 by ASME