Relationship Between Mechanical Properties and Wear Resistance of Alumina-Zirconia Ceramic Composites

Abstract

Mechanical behavior of Al₂O₃-based ceramics can be improved by dispersion of pure or partially stabilized ZrO₂ particles. The effective toughening or strengthening effect, which is operating in these composite materials, is determined by microstructural characteristics (composition, processing conditions) and environmental conditions (temperature, loading rate,…). The objective of this work has been to make a correlation between mechanical properties and wear resistance of alumina-zirconia composites. Wear tests were conducted employing a bloc-on-ring tribometer which consists of a steel ring rotating against plane ceramic specimens. Different environmental conditions were investigated: ambient air, and water. The wear volume is determined as a function of sliding distance. The dispersion of ZrO₂ particles in Al₂O₃ matrix improves the fracture behavior but reduces the wear resistance. However, the addition of ZrO₂ limits the water corrosion effect observed in Al₂O₃ materials. Wear seems to be controlled by the two material properties: hardness and fracture toughness. The increase of toughness due to toughening mechanisms counter balance the effect of hardness decrease on the wear resistance.