Effect of Oxide Additives on Phase Evolution and Tribological Behavior of Zirconia-Toughened Alumina Composite

Four different zirconia-toughened alumina added with different pairs of oxides (CeO2, TiO2, CuO, ZnO and SnO2) were prepared through the co-precipitation technique. Conventional sintering resulted in relative densities 96%. Phase analyses of these composites were performed by x-ray diffraction. Vicker's hardness and tribological behavior of all ZTA composites were studied. Microstructure analysis of polished and worn surfaces was carried out to understand and correlate the mechanical/tribological behavior with the microstructure. A different wear mechanism is observed in ZTA containing CeO2 and TiO2 which resulted in considerable improvement in tribological behavior with a minimum specific wear rate of 9 x 10(-7) mm(3)/Nm.