As-deformed filament's density and transport currents of MgB2/Ti/Glidcop wire

Filamentary MgB2/Ti/Glidcop wire has been manufactured by in situ process using hydrostatic extrusion, cold drawing and finally subjected to high pressure and standard densifications. Filament density of as-deformed wires was evaluated by micro-hardness measurements and related to applied deformation. It was found that filament's density and uniformity in as-deformed wire have a strong effect on the critical current density (Jc) of annealed samples. The highest Jc was measured for the filaments densified by cold isostatic pressing with 2 GPa and also for rotary swaged ones showing the best uniformity. Presented results showed the importance of filament density and homogeneity and also demonstrate suitability of hydrostatic extrusion for uniform long-length filamentary MgB2 wires production.

• In this study we examine the filament density and transport currents of 30-filament MgB2/Ti/Glidcop superconducting wire.
• We examine the effect of filament densification by high pressure treatment and by standard deformation techniques.
• In this study we conclude that filament density and uniformity of drawn filamentary wire can be increased effectively by rotary swaging, which allows high critical currents after final annealing.