GRAIN DELAMINATION OF AG-DOPED YBA2CU3O7-X SUPERCONDUCTOR

Silver-added YBa2Cu3O7-x(Y123) composites have been prepared for study of the effects of noble metal on the fracturing of Y123 grains. The microscopic results show that the planar-type microcracks are frequently found in large Y123 grains, which are delaminated by a uniaxial pressure as low as 150 MPa. Planar-type microcracks, characterized by the Wulff Net operation, are laid on the basal (001) plane which is the weakest plane in the Y123 crystal system. The formation of glassy material above eutectic temperature, the effect of Ag on green density, eutectic liquid, and the reaction of Ag grains with glassy material will be discussed. Moreover, compression tests of Ag/Y123 depict that more than 20 vol% silver additive can improve the ductility of the composite and prevent delamination of large Y123 grains.