Al2O3-ZrO2 debris life cycle during wear: Effects of the third body on wear and friction

Wear debris of alumina-zirconia materials generated during wear by abrasion and chipping (ring on disk) were analyzed in order to study their life cycle and their effects on wear and friction. When generated in the contact, wear debris contributed to redistribute the applied load on more contact points and absorbed a part of the energy provided to the system by microcracking and plastic deformation. The result was a decrease in the wear rate and an increase in the shear stress at the interface and, consequently, in the coefficient of friction. Inversely, removing debris from the contact did increase the wear. T.G.A., D.T.A., temperature measurements at the mid-thickness of the disk and debris morphology observations allowed us to detect some plastic deformation and a small hydration of the debris. Most of the plastic deformation occurred in zirconia particles since they became amorphous during wear by chipping. Hydration remains a minor phenomenon as the temperature is high at the interface. (C) Elsevier Science S.A.