Fracture Toughness and Slow Crack Growth Behavior of Ni-YSZ and YSZ as a Function of Porosity and Temperature

Improving the fracture toughness of stabilized zirconia-based solid oxide cells fuel electrode supports: Effects of type and concentration of stabilizer(s)

“…On the other hand, the fracture toughness of the reduced samples decreased dramatically when heated to 800 °C, as is also observed in [18,65]. This observation can be explained by the lower stiffness and yield stress of Ni at 800 °C.…”

“…The significantly higher room temperature fracture toughness of the reduced samples compared to the samples in the oxidized form shows that presence of highly ductile Ni phase overshadows the effect of the higher porosity. The toughening effect from the plastic deformation of the Ni-phase in Ni-SZ SOC supports is well-known [18,65]. Moreover, the high ductility of Ni resulted in comparable fracture toughness of tetragonal and cubic zirconia based supports (Figure 6), in contrast to the differences observed among the samples in the oxidized state (see Figure 3).…”

Time independent and time dependent probability of failure of solid oxide fuel cells by stress analysis and the Weibull method

“…Delayed failure of brittle materials such as 8YSZ due to subcritical crack growth (SCG) over time is a well documented phenomena with researchers such as Lowrie et al [14], Radovic et al [22] and Choi et al [7,6] all observing SCG effects in YSZ and LSM at room temperature and SOFC operating temperatures. The CARES computer code is able to accommodate SCG by assuming that flaws grow in size as a function of stress and temperature according to a power law, thus lowering the critical stress intensity required to produce fracture over time.…”

Fracture Toughness of Plasma‐Sprayed Thermal Barrier Ceramics: Influence of Processing, Microstructure, and Thermal Aging

“…. For fracture toughness measurements, the double torsion method was employed, which in recent years has proven to be a reliable technique for porous and microcracked ceramics . One issue with the test method, however, is that it measures the crack propagation resistance in the out‐of‐plane direction (parallel to the spray direction), whereas the in‐plane fracture behavior is more design‐relevant for conventional APS TBCs from the perspective of delamination failure.…”