Preparation of (Bi, Pb)-2223/Ag tapes by high temperature sintering and post-annealing process

摘要: Abstract A novel heat treatment process was developed to fabricate (Bi, Pb)-2223/Ag tapes with high critical current density ( J c ). The can be divided into two parts: reformation and post-annealing. Tapes were first heated the maximum temperature (830–860 °C) followed by slow cooling (reformation). Then, annealed between 760 820 °C (post-annealing). Reformation is expected produce a large amount of liquid phase which may heal microcracks, decrease porosity, improve grain growth. However, since sintering beyond Bi-2223 single-phase region, much Bi-2212 secondary phases will appear at boundaries. During post-annealing, these convert Pb)-2212 even Bi-2223. Hence, values for are significantly improved. microstructure composition investigated high-energy synchrotron XRD SEM/EDX. Some parameters e.g. temperature, rate, post-annealing time optimised.