Optimization of sintering conditions on the Bi-2223 formation and grain size

Phases equilibrium between Bi-2201, Bi-2212 and Bi-2223 phases has been established depending on the sintering time and the sintering temperature. Starting with calcined powder (820°C/24 h), optimization of sintering conditions (temperature, time and intermediate milling) has been achieved. Three sintering steps are necessary to obtain high Bi-2223 phase content. The sintering conditions can be described as follows: 100 h at 850°C, first intermediate milling, 25 h at 850°C, second intermediate milling and 25 h at 835°C. The final Bi-2223 phase content reaches 93% with a resulting grain size between 2 and 3 μm.