Abstract
In order to estimate the distribution of fracture toughness in ceramic-metal functionally graded material (FGM), fracture toughness and fracture behavior are investigated on ceramics-metal composite materials which correspond to each region of FGM. The materials are fabricated by powder metallurgy using partially stabilized zirconia (PSZ) and stainless steel SUS 304. Fracture toughness tests are conducted by three-point-bending on a rectangular specimen with a sharp edge-notch. The fracture toughness obtained for the non-graded composites increases with an increase in a volume fraction of SUS 304 metal phase. The fracture toughness of the non-graded composites is slightly lower than that obtained previously by stable crack growth in FGM. The difference in fracture toughness between the non-graded composites and FGM seems to be attributed to residual stress created during fabrication in FGM.
