Model for Estimating Wear Transition Loads in Ceramics
The wear behavior of advanced ceramics (alumina, silicon nitride, and silcon carbide) changes as the load or the coefficient of friction is increased. This change is associated with a drastic increase in wear rate at a critical load that depends on the material and test conditions. This transition from mild to severe wear occurs through a microfracture process at the sliding contact. Contact mechanics is used to develop a simple model to determine whether contact failure occurs by a classical brittle processes (i.e., cone cracking) or a quasi plastic behavior (i.e., small microcracks distributed below the contact surface). The model provides estimates of the transition load within a factor of two of the experimentally obtained values and indicates that the brittle behavior dominates the observed mild to severe wear transition in the three ceramics evaluated in this study.
Austrib 2002 : proceedings of the International Tribology Conference