Interactions Among Friction, Wear, and System Stiffness—Part 1: Effect of Normal Load and System Stiffness

Dry frictional contact between two metallic surfaces, one cast iron and the other steel, is analyzed. The experiments were conducted using a pin-on-disk setup instrumented with force and acceleration transducers. The interactions between friction, wear, and vibrations and their dependence on normal load and system stiffness are investigated. The results indicate that stiffness has a significant effect on the normal load at which transition takes place from mild to severe friction and wear. The variation of surface roughness with normal load for different stiffnesses is also examined. The different regimes of friction are observed, as the normal load is increased. They are characterized as steady state friction region, nonlinear friction region, region of transient friction with disturbances and region of self-excited vibrations. It is shown that the transition from the steady-state friction can be characterized by a sudden increase in the coefficient of friction and amplitude of slider oscillations.