Debris growth and migration in the slider-disk interface

A debris causing serious wear and spacing deviation is often attached to, or slipping slowly on the slider. Its motion is dominated by contact forces, especially by the angle of the contact force with respect to the slider surface. The contact forces can be high if the debris is compressed as it slips. This occurs most often when the pitch (or wall-angle) is about 10/spl deg/. The debris may be dislodged when the angles of contact forces change, especially due to skew. A simple model is developed to predict the tendency of debris motion, given the coefficient of friction, the skew, and the pitch angle. The model is programmed in Excel spreadsheet. The results are verified by experiments.