OTHER PAPERS |
Masaru TOMITA
This report summarizes the present status of resin impregnation technique for bulk high-temperature superconductors. The maximum trapped field is essentially limited by their mechanical strength of bulk high-temperature superconductors. The stress produced by refrigeration sometimes causes cracking. A large electromagnetic force also acts on the superconductors when they trap large magnetic fields, which occasionally leads to device failure. Epoxy resin can penetrate into bulk superconductors under certain conditions. Microstructural observation revealed that microcracks as well as porosities can be impregnated with epoxy resin, which greatly improves mechanical properties and thus results in the improvement of field trapping capability. Resin-impregnated bulk high-temperature materials have already been used for several practical applications.
Copyright (c) 2003 Railway Technical Research Institute