Fracture resistance curve behavior of multilayered alumina–zirconia composites produced by centrifugation Original Research Article

The single-edge-V-notched-beam (SEVNB) testing method was used to measure the crack growth resistance (R-curve) behavior of multilayered alumina–zirconia composites. Crack initiation and extension from the V-notch tip were observed via in situ optical microscopy. The resulting R-curves were compared with an R-curve measured from a monolithic composite having a similar composition and a homogeneous microstructure, where the influence of layer–layer interfaces, gradient microstructures, and the direction of crack propagation on the resulting R-curves were observed. Additionally, the stress intensity factor for crack initiation from the V-notch tip was ∼0.2 MPa·m1/2 higher than the stress intensity factor to further extend this crack.