Fully dense, bulk Bi2Sr1.7CaCu2Ox (2212) superconductor pellets were made by hot isostatic pressing in an inert atmosphere. Electron microscopy revealed that rotation and bending of the platelike 2212 grains were responsible for much of the densification. Under processing conditions of 825°C and 105 MPa, dense pellets were obtained in 15 min. Many dislocations, planar faults, and, perhaps, intergrowths of the Bi2Sr2CuOx phase were produced during pressing. The dislocations were largely present in subgrain boundaries when the pressing times were increased to 45–120 min.

Generaly silver doping into YBa2Cu3O7 superconductor improves the critical temperature and critical current density. In this work the silver peroxide was doped into YBa2Cu4O8 superconductor and sintered by the Oxygen Hot Isostatically Pressing method. The critical temperature of the 124 phase increased by silver peroxide doping.

The bismuth-based 2212 and 2223 superconductors and the yttrium-based 123 and 124 high Tc superconductors are oxide ceramics, so that oxidizing conditions must be maintained in the HIP to avoid oxygen loss and decomposition. This has been done in an argon gas HIP by using glass encapsulation, but internal gas pressure retards densification. The thermodynamics of the release of oxygen by the superconductive ceramics and the stability of the metal to oxygen can be shown on a free energy diagram (Ellingham diagram). The base metals (as Fe and Cu) are reactive with respect to superconductive ceramics but not silver.