Effect of SiC and Sintering Temperature Variations on the Characteristic of Fe-Sheathed MgB2 Superconductor Wires

Abstract

MgB2superconductor with relatively high critical temperature (Tc=40 K) has been developed for possibilities utilization in various practical applications such as Magnetic Resonance Imaging. In order to enhance the process, the material was prepared by Powder-In-Tube (PIT) method, while the superconducting properties was improved by incorporating 0 wt.%, 10 wt.% and 20 wt.% SiC nanoparticles into MgB2structure. This study aimed at analyzing the effect of sintering temperature on the microstructure, resistivity and phase of Fe-sheathed MgB2superconducting wires. Three different compositions of MgB2powders were inserted into Fe tube with inner ø of 4 mm and outer ø of 6 mm. This tube was then rolled and drawn into a ø 2.5 mm wire. Wire samples with three different compositions of SiC were heat treated at 600°C and 800°C respectively. All samples were characterized to analyze the morphology, resistivity and crystal structure. X-ray diffraction (XRD) analysis showed that some Mg may react with SiC to form MgSi and with oxygen to form MgO. Scanning electron microscope (SEM) images revealed that with no addition of SiC, MgB2was formed and dispersed uniformly in wire, but with 10 wt.% and 20 wt.% SiC nanoparticles, the whisker morphology was observed resulting in degradation of the superconducting properties.