화학공학소재연구정보센터
Journal of the American Ceramic Society, Vol.102, No.3, 1083-1089, 2019
Towards a sustainable fabrication of cryomagnets: Melting-driving approaches for recycling failed REBa2Cu3Ox bulks
Recycling failed REBa2Cu3Ox (RE123 or REBCO, RE: rare earth elements) bulks is a matter of significant importance in the manufacture of superconducting cryomagnets for practical applications. However, bulks with high solid fraction and high T-p (peritectic temperature) are difficult to recycle. In order to solve this problem, we first gave a comprehensive classification of failed bulks based on their macrostructures, determined by the volume ratio between poly-crystalline grains (PCG) and solidified liquid phase (SLP) of the bulks, which is positively correlated with the difficulty level of melting the bulks. Furthermore, particularly for hard-to-melt samples, we developed a novel melting-driving recycling process, in which an additional step, high-temperature remelting plus quenching, was employed before a normal regrowing step. As a result, we succeeded in recycling the failed SmBCO bulks featuring high T-p and structures of fully-grown PCG, which demonstrated comparable superconducting performance to ones prepared by normal top-seeded melt-growth. This study opens a new direction of recycling all kinds of failed RE123 bulks and other ceramic materials, making their industrial applications more sustainable and economic.