CRACK RESISTANCE AND FATIGUE OF TRANSFORMING CERAMICS .2. CEO2-STABILIZED TETRAGONAL ZRO2

Crack resistance characteristics and fatigue properties have been investigated in Ce-TZP ceramics with different grain sizes. The relatively low critical transformation stress allows the development of larger transformation zones (less-than-or-equal-to 200-mu-m), leading to flaw-tolerant behavior. However, autocatalytic transformation processes are found to be bound to grain sizes beyond a critical value; transformation is then very limited in finer microstructures. Fatigue as a specific cyclic effect is more pronounced in microstructures with larger grains. Thus, damaging processes in the course of extensive t-m transformation are suspected to be intensified during cyclic loading.