TY - JOUR
T1 - Phase evolution during the melting and recrystallization of ceramic core in the (Bi,Pb)-2223 tape
AU - Li, J. Y.
AU - Soubeyroux, L.
AU - Zheng, H. L.
AU - Li, C. S.
AU - Lu, Y. F.
AU - Porcar, L.
AU - Tournier, R.
AU - Zhou, L.
PY - 2006/12/15
Y1 - 2006/12/15
N2 - The phase evolution during melting and recrystallization of (Bi,Pb)2Sr2Ca2Cu3O10 ((Bi,Pb)-2223) core in a Ag-sheathed monofilamentary tape has been investigated. The tape was fabricated by PIT process with powders containing nearly pure (Bi,Pb)-2223 phase. Short samples were melted at 805 °C, 808 °C, 812 °C, 816 °C, 831 °C, slowly cooled at 1.5 °C/h under flowing 1.6% O2 balanced with argon 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. The results show that (Bi,Pb)-2223 core is partially melted into a liquid and alkaline earth cuprates (AECs), mainly 2:1-AEC, at 805 °C, 808 °C, 812 °C, and well reforms directly from the melt during the slow cooling. More (Bi,Pb)-2223 phase is decomposed at temperatures higher than 816 °C, but cannot recrystallize, indicating that a partial melting at some temperatures around a given temperature range is essential to (Bi,Pb)-2223 phase reformation. The melt composition moves from that between "2223" and "2212" stoichiometries towards 2212-like stoichiometry with increasing temperature. 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-AEC plays the most important role in (Bi,Pb)-2223 melt-recrystallization 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.
AB - The phase evolution during melting and recrystallization of (Bi,Pb)2Sr2Ca2Cu3O10 ((Bi,Pb)-2223) core in a Ag-sheathed monofilamentary tape has been investigated. The tape was fabricated by PIT process with powders containing nearly pure (Bi,Pb)-2223 phase. Short samples were melted at 805 °C, 808 °C, 812 °C, 816 °C, 831 °C, slowly cooled at 1.5 °C/h under flowing 1.6% O2 balanced with argon 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. The results show that (Bi,Pb)-2223 core is partially melted into a liquid and alkaline earth cuprates (AECs), mainly 2:1-AEC, at 805 °C, 808 °C, 812 °C, and well reforms directly from the melt during the slow cooling. More (Bi,Pb)-2223 phase is decomposed at temperatures higher than 816 °C, but cannot recrystallize, indicating that a partial melting at some temperatures around a given temperature range is essential to (Bi,Pb)-2223 phase reformation. The melt composition moves from that between "2223" and "2212" stoichiometries towards 2212-like stoichiometry with increasing temperature. 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-AEC plays the most important role in (Bi,Pb)-2223 melt-recrystallization 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.
KW - (Bi,Pb)-2223/Ag tape
KW - Melting and recrystallization
KW - Phase evolution
UR - http://www.scopus.com/inward/record.url?scp=33845318863&partnerID=8YFLogxK
U2 - 10.1016/j.physc.2006.08.010
DO - 10.1016/j.physc.2006.08.010
M3 - 文章
AN - SCOPUS:33845318863
SN - 0921-4534
VL - 450
SP - 56
EP - 60
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
IS - 1-2
ER -