Influence of defects on the high temperature mechanical behaviour of yttria fully-stabilized zirconia single crystals

This work is focused on the study of the influence of high temperature heat treatments given prior to deformation in yttria fully-stabilized zirconia single crystals (YFSZ). Experimental results show that the yield stress fou nd in constant strain tests performed in heat-treated samples is remarkably dependent on the annealing time when the treatment is given under a very l ow oxygen pressure atmosphere. This phenomenon has been explained through t he analysis of the thermodynamics of complex defects found at high temperat ure, as well as the interaction between mobile dislocations with them durin g plastic deformation.