Strength Degradation from Contact Fatigue in Self-toughened Glass-Ceramics

Abstract

We investigated strength degradations from cyclic contact fatigue in self-toughened glass-ceramics. Hertzian indentation was used to induce cyclic contact load. Dynamic fatigue was also performed with changing stress rates form 0.01 to 10000 MPa/sec. After that, strength data and fracture origins were analysed. As the number of contact cycles increased or stressing rate decreased, severe strength degradation occurred by as much as 50% because of radial cracks developed form microcrack coalescence