Ex-situ powder in tube manufacturing process is based on the filling of a metal sheath with pre-synthesized MgB2 powders. It is necessary for MgB2 used in wire manufacturing to have the required properties of grain size and connectivity. Synthesis temperature for MgB2 is an important parameter to improve the quality of powders and subsequently enhance performances of wire for large-scale applications. In this work we investigated the effect of synthesis temperature on morphology, and how this is reflected on superconducting properties. A detailed study on the influence of MgB2 synthesis temperature on grain size has been given, evaluated through SEM images and magnetic measurement. As predicted higher synthesis temperature led to an enhancement in average grain size, but the effect is slightly appreciable. It has been applied a model for average grain size distribution based on the penetration of magnetic field in the superconductor, that was found to be in agreement with several other methodologies, in order to have a confirm of image analysis. Engineering current density has been evaluated from direct measurement using a four-probe configuration, where best results have been reported for sample synthesized at 950 °C, with engineering current density of 3 × 105 A/cm2 at 2 T, almost two times the value of sample synthesized at 750 °C at the same field.
Synthesis temperature effects on ex-situ manufactured MgB 2 wires useful for power applications
Gianmarco Bovone;Cristina Bernini;Emilio Bellingeri;Andrea Malagoli;Maurizio Vignolo
2015
Abstract
Ex-situ powder in tube manufacturing process is based on the filling of a metal sheath with pre-synthesized MgB2 powders. It is necessary for MgB2 used in wire manufacturing to have the required properties of grain size and connectivity. Synthesis temperature for MgB2 is an important parameter to improve the quality of powders and subsequently enhance performances of wire for large-scale applications. In this work we investigated the effect of synthesis temperature on morphology, and how this is reflected on superconducting properties. A detailed study on the influence of MgB2 synthesis temperature on grain size has been given, evaluated through SEM images and magnetic measurement. As predicted higher synthesis temperature led to an enhancement in average grain size, but the effect is slightly appreciable. It has been applied a model for average grain size distribution based on the penetration of magnetic field in the superconductor, that was found to be in agreement with several other methodologies, in order to have a confirm of image analysis. Engineering current density has been evaluated from direct measurement using a four-probe configuration, where best results have been reported for sample synthesized at 950 °C, with engineering current density of 3 × 105 A/cm2 at 2 T, almost two times the value of sample synthesized at 750 °C at the same field.File | Dimensione | Formato | |
---|---|---|---|
prod_342461-doc_125020.pdf
non disponibili
Descrizione: Synthesis temperature effects on ex-situ manufactured MgB2 wires useful for power applications
Tipologia:
Versione Editoriale (PDF)
Dimensione
1.35 MB
Formato
Adobe PDF
|
1.35 MB | Adobe PDF | Visualizza/Apri Richiedi una copia |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.