The phase evolution during melting and recrystallization of ceramic core in Ag-sheathed (Bi,Pb)-2223 monofilamentary tape has been studied. The tape was fabricated by PIT process with powders containing nearly pure (Bi,Pb)-2223 phase. Short samples were melted at 805ºC, 808ºC, 812ºC, 816ºC and 831ºC, slowly cooled down at 1.5ºC/hr. and quenched in air at room temperature. X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) were applied for the phase identification. XRD patterns of samples show that (Bi,Pb)-2223 core is partially melted at 805ºC, 808ºC, 812ºC, and well reformed directly from the melt during the slow cooling. More (Bi,Pb)-2223 phase is decomposed at temperatures higher than 816ºC and can not recrystallize, indicating that a partial melting at some temperatures around a given temperature range is essential for (Bi,Pb)-2223 phase reformation. The results of EDS analysis show that the melt composition moves from that between "2223" and "2212" stoichiometries towards 2212-like stoichiometry with increasing temperature, and Bi-containing 2:1 phase is the main secondary phase. This seems to lead to the conclusion that (Bi,Pb)-2223 phase decomposes incongruently into a 2212-like liquid and (Ca,Sr)-cuprates. 2:1 phase plays the most important role in (Bi,Pb)-2223 meltrecrystallization process. Our results also reveal that plate-like shape (Bi,Pb)-2223 grains can be obtained via melting and recrystallization if the optimum processing conditions are used.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.