Determination of internal strains in high-temperature superconductor composites by intense pulsed neutron source

Results are presented for the effect of silver (Ag) addition on microstructure, mechanical properties, and internal strains in YBa2Cu3O(7-delta)-Ag superconducting composites. A 2.2 fold increase in strength was obtained as a result of approx. 20 vol percent Ag addition to YBa2Cu3O(7-delta) without any adverse effects on superconducting properties. The increase in strength is believed to be due to an increase in density as well as due to the development of internal compressive strains in the YBa2Cu3O(7-delta) matrix as a result of Ag addition. The internal strains developed due to thermal expansion mismatch between YBa2Cu3O(7-delta) and Ag were measured by neutron diffraction using Intense Pulsed Neutron Source at Argonne National Laboratory. Creep may play an important role in relaxing the residual strains in composite constituents.