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

The effects of the calcination conditions (time, temperature, intermediate milling) on the kinetics of formation of Bi-2223 and on the grain size were studied using a powder precursor synthesized by the polymer matrix method. The samples were characterized by XRD and SEM analysis. The grain size and the kinetics of formation of Bi-2223 strongly depend on the calcination conditions and thus on the phase assemblages formed at the end of the calcination that determines the reactivity during sintering. The higher the calcination temperature is the larger the grain size. We have observed that 24 h of calcination at 820 °C without intermediate milling allows one to obtain 79% of Bi-2223 phase in 60 h of sintering at 835 °C.