SiC doped MgB2 wires in a Ti sheath prepared by stage formation

摘要

The sintering effect between deformation steps - stage formation (SF) - of SiC doped in situ (IS) MgB2 wires deformed in a Ti sheath was studied. The samples were prepared by two-axial rolling (TAR) deformation. Titanium as a sheath material allows the use of higher sintering temperatures with a relatively low reaction layer with the sheath. Critical current densities (JC) were measured at temperatures of 4.2 and 15K in external magnetic fields ranging up to 15T. The critical temperatures, transport properties and overall porosities of the reference and SF samples are compared and discussed. The highest transport properties were measured for SF wires post annealed at 800 and 850 °C having also relatively high Tc = 36.1K, which is important for the dry-cooling operation. The results presented show that stage formation could be prospectively used for high-field and higher temperature (～20K) applications of the MgB2 superconductor.