The effect of applying a uniaxial stress, while varying the temperature and the time of sinter-forging, on the microstructure and critical current density of the sinter-forged YBa2Cu3O7−x ceramics has been investigated. Spray-roasted powders from a nitrate-based feed solution were prepared as the starting materials. By applying a relatively low uniaxial stress (2 MPa), the sintered density increased up to 95% of the maximum value. Critical current densities of between 360 and 420 A cm−2 were obtained for the sinter-forged samples which are significantly higher than values reported for pressureless-sintered samples prepared from solid-state reacted powders (typically 70 A cm−2). This increase in the density of the material and the critical current density can be explained by the alignment of the elongated YBa2Cu3O7−x grains under applied uniaxial stress during sintering. The elongated YBa2Cu3O7−x grains have been characterized by transmission electron microscopy.
Polymer Microstructure Microscopy Electron Microscopy Transmission Electron Microscopy
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