Improved mechanical properties through recycling of Y-Ba-Cu-O bulk superconductors. Issue 6 (June 2021)

• Record Type: Journal Article
• Authors: Namburi, Devendra K.; Singh, Kirti; Huang, Kai Yuan; Neelakantan, Suresh; Durrell, John H.; Cardwell, David A.
• Is Part Of: Journal of the European Ceramic Society. Volume 41:Issue 6(2021)
• Page Start: 3480
• Page End: 3492
• Publication Date: 2021-06
• Subjects: High temperature superconductors -- Recycling technique -- YBCO bulk -- Mechanical properties -- Microstructure -- Trapped field -- Single grain; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2021.01.009
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: The success rate of the growth of single grain Y–Ba–Cu–O (YBCO) bulk superconductors, applied typically as trapped field magnets, by melt processing techniques is often rather low. To ensure that the rare earth elements used in these materials are not wasted, and to improve the economics of production, therefore, an effective way of recycling such "failed" samples is essential for the long-term sustainability of the bulk process. In the present paper, a detailed study of the microstructural and mechanical properties of recycled YBCO samples has been made and their properties compared to those of primary grown samples. Recycled YBCO samples exhibit trapped magnetic fields of ∼ 70 – 80 % of those observed in primary grown samples. Microstructural investigations reveal a significant reduction in the porosity and a simultaneous improvement in the distribution of Y2 BaCuO5 second phase inclusions throughout the microstructure of recycled, single grain YBCO samples. This means that, while the superconducting properties of the recycled samples are generally inferior to those of primary grown samples, somewhat surprisingly the mechanical properties such as flexural strength, hardness and tensile strength of the recycled samples can be improved. The recycled YBCO samples studied here exhibited an average flexural strength of 75 MPa, which is almost 50 % higher compared to primary grown YBCO, which has significant implications for their use in practical applications that involve large mechanical forces, such as levitation. Good correlations were observed between the microstructural parameters and measured mechanical properties in both primary grown and recycled YBCO samples.