Abstract
This paper describes the effects of the number of cracks and crack spacing on fatigue crack growth characteristics of PSZ ceramics, which are required in the strength reliability evaluation of ceramics component. Fatigue fracture toughness testing shows that the life of PSZ ceramics with multiple pre-cracks increases with increasing the number of cracks and the life of PSZ ceramics is changed by the crack spacing. Also as the crack spacing is larger, the growth of crack which does not lead to fracture is more significant. It is confirmed that a linear relationship between the fatigue crack growth rate da/dN and the stress intensity factor range Δ K is exhibited on a logarithmic scale for the PSZ ceramics with multiple cracks as in the case of a single crack. On the other hand, crack growth rate parameters m and -logC, for multiple cracks depend on the number of cracks and the crack spacing. Further, the effect of the number of cracks and crack spacing on statistical characteristics of crack growth rate parameters m and -logC, and fracture toughness value Kfc is discussed by Weibull distribution function.
