Mechanical properties of bulk superconductors

Abstract

Recent advancement in the bulk fabrication process has enabled the production of large single-grain bulk RE-Ba-Cu-O superconductors with high J c values, which can trap fields much higher than those associated with conventional permanent magnets. However, a large electromagnetic force acts on the bulk superconductors when they trap a large field, which sometimes leads to fatal fracture. In this study, we measured mechanical properties of single-domain Y-Ba-Cu-O and Sm-Ba-Cu-O bulk superconductors from the output of strain gauges glued directly to the sample surface. The stress was applied to the samples by reducing the external fields from 10 to 0 T at 50 K. It was found that Ag addition is effective in improving the mechanical properties of melt processed Y-Ba-Cu-O and Sm-Ba-Cu-O.

Effects of Ag addition on some physical properties of granular YBa2Cu3O7-δ superconductor

“…The Ag presence increases slightly the value from 140 to 150 GPa, but as also observed in the hardness profiles, the error bars are very large for all of the studied samples. The measured values of the elastic modulus in the present situation agree with the reported data [26][27][28][29][30][31][32] and the same interpretation of composite behavior can be used to interpret these results. 12 served.…”

“…The measured hardness in these cases corresponds to an averaged behavior between the superconductor ceramic, the metallic Ag grains and the presence of defects. Taking into account this composite character of ours samples, the present hardness profiles are in agreement with reports in the literature for Y-123 based structures where hardness varies from 4 to 12 GPa [26][27][28][29][30][31][32]. Consequently, the broad range of the reported values can then be attributed to the different sample processing conditions and also to the employed measurement technique, which in almost of all reported situations corresponds to the conventional Vickers method.…”

Mechanical characterization of melt-textured Y0.95Er0.05Ba2Cu3O7− superconductor prepared in air

“…The hardness reflects the composite nature of the superconductors, where it is observed Y-211 and BaCeO 3 particles in a Y-123 matrix. In the literature, it is reported a broad range of hardness, from 4 to 12 GPa [13,[16][17][18][19][20][21]. This broad dispersion is mainly due to dependence of the microstructure such as porosity and different phases on the different sample processing conditions.…”

Design of a Linear Bulk Superconductor Magnet Synchronous Motor for Electromagnetic Aircraft Launch Systems

“…The electromotive force (emf) induced in a single stator coil due to the magnetic field produced by the moving BSCs is calculated by (8) where is the phase a emf, is the phase a flux linkage, while denotes time. The emf induced in a single phase a coil is shown in Fig.…”

“…Also, increased values of trapped fields have been observed when Sm is used instead of Ba, along with some Ag [7]. Ag is added to the material to improve the mechanical strength of the bulk magnets [8]. Several levitation systems using bulk superconductor (BSC) magnets along with normal permanent magnets have been reported in the literature [9], [10].…”