Abstract
Bi-based superconducting shapes were fabricated by extrusion of ceramic-polymer mixture involving a solgel derived superconductor and in situ polymerized polymethylmethacrylate as binder. The powder was intimately mixed with methylmethacrylate monomer and polymerized in the presence of other organic additives such as butylbenzyl phthalate, phosphate ester and benzoyl peroxide. The viscous mass was then extruded to wires 3mm in diameter and 25mm in length. They were heat-treated at controlled rates for binder burn out and sintering at 840°C for 20h. Zone melting refining was carried out on the sintered samples in a three-zone furnace at a controlled speed of 30mm per hour for introducing texture. The surface morphology of starting powder and microstructure of fractured surface of sintered and textured wires are presented and compared.
