Influence of ZrO2 on the thermo-mechanical response of nano-ZTA

Zirconia dispersed alumina powders have been synthesized in homogenous condition by following the wet interaction process at varying ZrO2 content and the thermo-mechanical behavior of the same has been studied. The tetragonal phase is retained at room temperature without any deliberate addition of stabilizer, which has been explained on the basis of particle size effect in terms of lower surface energy of the t-phase compensating for the difference in chemical free energy. Flexural strength follows an inverse relation with temperature due to reduction of driving force for t → m transformation. The toughness and strength reduce significantly above 10 mol.% ZrO2 beyond which comparatively large grain growth is observed. The thermal expansion hysteresis associated with t → m transformation is evident with martensitic temperature influenced by ZrO2 content and grain size.