HIGH-TEMPERATURE CRACK-GROWTH IN Y-TZP

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