Cyclic Fatigue Behavior of Superplastic Diffusion Bonded Y-TZP and Y-TZP/Alumina Composite

Abstract

Cyclic bending fatigue tests were performed on Y-TZP, Y-TZP/Al₂O₃ composite (3Y20A), and superplastic diffusion-bonded materials. The relation between the maximum stress (σ_max) and the number of cycles to failure (N) was expressed as N=B/σ_maxⁿ. The fatigue exponents (n) of Y-TZP and 3Y20A were 26 and 61, respectively. Every fatigue specimen of 3Y20A-3Y20A bonded material was fractured at the bonding interface with the fatigue exponent of 24. In the fatigue test of TZP-TZP bonded material, 33% of specimens were fractured at the bonding interface with the fatigue exponent of 16. The fatigue exponent of TZP-TZP bonded materials which were fractured at Y-TZP part was the same with that of Y-TZP. When fracture occurred at the bonding interface, ground marks were observed on the fracture surface. The bonded materials were more susceptible to cyclic fatigue than the base materials.