Mechanical processing of highjcbscco superconductors

Abstract

Abstract High J c superconducting oxides can be obtained by processing polycrystalline powders to achieve high degrees of densification and sharp crystallographic textures characterized by the conducting crystallographic planes lying parallel to the direction of the current flow (i.e., in the plane of a conducting tape or parallel to the axis of a wire). In the present study, we investigate the densification and texture evolution in a Pb doped Bi—Sr—Ca—Cu oxide (BSCCO) under axisymmetric and plane strain (channel die) compression. Experimental measurements of the microstructural evolution, including crystallographic texture and grain morphology, are presented as a function of the degree of deformation and densification. The orientations of the conducting planes (c planes) are shown by measured X-ray pole figures and analyses of these orientations are given for both tests. A model based on crystal plasticity theory is proposed to simulate the inelastic deformation and texturing of the BSCCO oxide. Predicte...