Development of Multi-Filament Textured-Powder Bi-2212/Ag wire with enhanced LAR

TL;DR

This paper presents a novel fabrication process for Bi-2212/Ag superconducting wire that uses uni-axial compression of fine powder to improve texture and potentially reduce silver content, enhancing performance and cost-effectiveness.

Contribution

It introduces a new fabrication method involving uni-axial compression of fine Bi-2212 powder and billet extrusion to produce textured wire with improved alignment.

Findings

Texture >80% achieved with 200 MPa compression

Successful formation of billets with trapezoidal bars around Ag core

Ongoing testing shows promising performance improvements

Abstract

The performance and cost of Bi-2212/Ag wire is limited by the large fraction of silver matrix (~3:1) that is required in the oxide-powder-in-tube fabrication process. An alternative fabrication process is being developed in which fine-powder Bi-2212 is uni-axially compressed to form bars with a thin Ag foil sheath. The fine powder naturally textures (aligns the a-b planes perpendicular to the direction of compaction) with texture >80% using 200 MPa compression. A billet is formed by stacking trapezoidal-cross-section bars in a symmetric 8-12-16 pattern around a Ag rod and enclosing in a Ag-wall extrusion can. The billet is extruded and drawn to fine wire. Results are presented on present status of the development and testing.