The preparation route for Nickel-sheathed MgB2 tapes has been studied in order to achieve improved transport properties at temperatures above that of liquid helium. Superconducting tapes have been manufactured by the Powder-In-Tube method, that consists in the cold working of a Nickel tube filled by reacted MgB2 powders, and in a final heat treatment carried out in Argon atmosphere. The cold working procedure has been tuned in order to achieve the highest degree of MgB2 density, while limiting the formation of sausaging of the superconducting core cross section. The effect of the final heat treatment has been studied both on the superconducting and microstructural properties of the MgB2 tapes. The critical current of the reacted MgB2 tapes has been measured as a function of the magnetic field and of the temperature on short samples as well as on a small pancake coil. Finally, the microstructural and XRD analyses have revealed the clear presence of a MgB2Ni2.5 reaction layer between the Nickel sheath and the MgB2 superconducting core in the reacted samples
Fabrication and characterization of Ni-sheathed MgB2 superconducting tapes
2003
Abstract
The preparation route for Nickel-sheathed MgB2 tapes has been studied in order to achieve improved transport properties at temperatures above that of liquid helium. Superconducting tapes have been manufactured by the Powder-In-Tube method, that consists in the cold working of a Nickel tube filled by reacted MgB2 powders, and in a final heat treatment carried out in Argon atmosphere. The cold working procedure has been tuned in order to achieve the highest degree of MgB2 density, while limiting the formation of sausaging of the superconducting core cross section. The effect of the final heat treatment has been studied both on the superconducting and microstructural properties of the MgB2 tapes. The critical current of the reacted MgB2 tapes has been measured as a function of the magnetic field and of the temperature on short samples as well as on a small pancake coil. Finally, the microstructural and XRD analyses have revealed the clear presence of a MgB2Ni2.5 reaction layer between the Nickel sheath and the MgB2 superconducting core in the reacted samplesI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
