TY - JOUR
T1 - Preparation of (Bi, Pb)-2223/Ag tapes by high temperature sintering and post-annealing process
AU - Hua, L.
AU - Grivel, Jean-Claude
AU - Andersen, L.G.
AU - Tschentscher, T.
AU - Wang, W.G.
AU - Hansen, J.B.
PY - 2002
Y1 - 2002
N2 - A novel heat treatment process was developed to fabricate (Bi, Pb)-2223/Ag tapes with high critical current density (J(c)). The process can be divided into two parts: reformation and post-annealing. Tapes were first heated to the maximum temperature (830-860 degreesC) followed by slow cooling (reformation). Then, tape, were annealed between 760 and 820 degreesC (post-annealing). Reformation is expected to produce a large amount of liquid phase which may heat microcracks, decrease porosity, and improve grain growth. However, since the sintering temperature is beyond the Bi-2223 single-phase region, much Bi-2212 and secondary phases will appear at the Bi-2223 brain boundaries. During post-annealing. these phases may convert to (Bi, Pb)-2212 and even to Bi-2223. Hence, the J(c) values for these tapes are significantly improved. The microstructure and the phase composition were investigated by high-energy synchrotron XRD and SEM/EDX. Some process parameters e.g. sintering temperature. cooling rate. and post-annealing time were optimised. (C) 2002 Elsevier Science B.V. All rights reserved.
AB - A novel heat treatment process was developed to fabricate (Bi, Pb)-2223/Ag tapes with high critical current density (J(c)). The process can be divided into two parts: reformation and post-annealing. Tapes were first heated to the maximum temperature (830-860 degreesC) followed by slow cooling (reformation). Then, tape, were annealed between 760 and 820 degreesC (post-annealing). Reformation is expected to produce a large amount of liquid phase which may heat microcracks, decrease porosity, and improve grain growth. However, since the sintering temperature is beyond the Bi-2223 single-phase region, much Bi-2212 and secondary phases will appear at the Bi-2223 brain boundaries. During post-annealing. these phases may convert to (Bi, Pb)-2212 and even to Bi-2223. Hence, the J(c) values for these tapes are significantly improved. The microstructure and the phase composition were investigated by high-energy synchrotron XRD and SEM/EDX. Some process parameters e.g. sintering temperature. cooling rate. and post-annealing time were optimised. (C) 2002 Elsevier Science B.V. All rights reserved.
KW - 5-I nano
U2 - 10.1016/S0921-4534(02)00806-7
DO - 10.1016/S0921-4534(02)00806-7
M3 - Journal article
SN - 0921-4534
VL - 372-376
SP - 608
EP - 611
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
ER -