The effect of mechanical deformation on the phase transformation of BSCCO superconductors

Abstract

Mechanical deformation has been widely used to produce textured microstructures to improve the critical current density of Bi2223 superconducting tapes. However, the effect of mechanical deformation on the phase transformation of the BSCCO system has not been well understood. The present research studies the relations between mechanical deformation and the phase transformation kinetics. The results showed that the Bi2223 phase abundance firstly decreased when the mechanical deformation was increased from 20% to 60%, and then increased as the deformation was increased above 60%. The 60% thickness reduction, therefore, resulted in the lowest Bi2223 phase abundance. The effects of mechanical deformation on the distribution of the Bi2223 phase across the thickness of the tape and the grain size of Bi2223 and Bi2212 phases were also studied. The experimental results have been explained by considering the different dominant energies associated with the different mechanical deformation regimes.