The development of high fracture toughness YBa2Cu3O7−x/Ag composites

Microstructural refinement of the YBa2Cu3O7−x/Ag superconductor composite has resulted in a fracture toughness of 3.6 MPa √ms, as measured by single edge notch beam fracture specimens. This represents the highest bulk fracture toughness value published to date for silver compositions near 20%. A combination of grain size and porosity refinement, in addition to control of silver morphology and distribution, permits the development of fracture toughness levels that compare favorably with many structural ceramics such as SiC and Al2O3.