Conventional solid-state reaction technique was used to prepare bulk samples with nominal composition of (Bi, Pb)2Sr2Ca2Cu3O10+δ superconductors. The prepared powder was pelletized at different pressure (P = 0.3, 0.7, 1.0, 1.4 and 1.9 GPa) before the calcination process. Structural parameters and phase purity were evaluated using x-ray diffraction (XRD). The formation of the tetragonal major phase is improved with increasing the pelletization pressure up to 1.4 GPa. The morphology and elemental compositions were performed by using scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDX), respectively. The results showed the enhancement of the grain alignment at an optimum pelletization pressure of 1.4 GPa with a decrease in the porosity percentages. Superconducting transition temperature (Tc) and the critical current density (Jc) were obtained by means of DC electrical resistivity and the voltage-current characteristic, respectively. Both Tc and Jc are improved with increase the pelletization pressure up to 1.4 GPa. Room temperature Vickers microhardness Hv measurement was performed at different applied loads (0.245–9.8 N) and times (10–60 s). As a result of the Hv measurements, all the prepared samples have a normal indentation size effect behaviour. It was found that P = 1.4 GPa was the optimal pressure to improve the microhardness in the (Bi, Pb)-2223 phase. The measured Hv data were theoretically analysed using Meyer’s law, the Hays-Kendall approach, the elastic plastic deformation model and the proportional sample resistance. The last model was recognized to be the best theoretical one describing the true Hv values for the considered phase. Room temperature indentation creep analysis was also performed using time-dependent microhardness to identify the operative creep mechanisms in the measured samples.

The corrosion behaviour of (Bi, Pb)-2223 samples compacted at 0.3–1.9 GPa in 0.5 M of HCl, NaCl, and NaOH solutions at 30 °C was investigated using potentiodynamic polarization curves measurements and electrochemical impedance spectroscopy (EIS) technique as well as scanning electron microscopy (SEM) and energy dispersive X-ray emission spectroscopy (EDX). Polarization results showed that the increase in compaction decreases both cathodic hydrogen evolution or oxygen reduction and anodic (BiPb)-2223 superconductor dissolution in 0.5 M HCl, and 0.5 M NaOH. On the other hand, compaction mainly affects the anodic part of the polarization curves of (Bi, Pb)-2223 in 0.5 M NaCl solution. EIS measurements revealed that the highest protection of the superconductors was achieved in 0.5 M NaCl, while the lowest degree of protection was observed in 0.5 M HCl. SEM images show a random plate-like morphology fitted with the marker of (Bi, Pb)-2223 material. The compacted sample at 1.9 GPa indicates deformation of the grains and the formation of a micro-crack. The corrosion mechanism of the superconductor at different pH values was also discussed.