High-temperature crack growth in Y-TZP

Fatigue and static crack growth is studied in Y-TZP at intermediate temperatures. Fractographic observations indicate that a reduction in interfacial fracture energy, which induces intergranular fracture at intermediate temperatures, is responsible for a decrease in crack propagation thresholds and fracture toughness. Static and cyclic growth rates increase with temperature. Although cyclic loading in the near-threshold regime promotes crack propagation, cyclic crack growth velocities for higher values of K are slower than predictions based upon static crack growth results. (C) 1997 Elsevier Science S.A.