Liquid phase assisted superplastic deformation of TiO2-doped ZTA ceramics

Abstract

In this study, the compressive deformation of zirconia toughened alumina (ZTA) ceramics doped with different amounts of TiO2 dopants were investigated in the temperature range of 1300-1400 °C to evaluate the stress exponent (Q value) and apparent deformation activation energy (Q value). With 0-8 wt.% TiO2 dopants, the n values and Q values of the TiO2-doped ZTA ceramics were calculated as 2-3 and 605-749 kJ/mol, respectively. Moreover, three grain boundary features were observed in these deformed materials, named the clean grain boundary, thin liquid phase grain boundary, and thick liquid phase grain boundary. Based on the deformation behavior and microstructure evolution, it was found that the lower apparent activation energy and higher strain rate of TiO2-doped ZTA ceramics are intensively related to the grain boundary feature.