Fabrication of Ti doped MgB2/Cu superconducting wires by SHS method in an unsealed furnace

Mg0.9Ti0.1B2/Cu wires have been successfully synthesized by the powder-in-tube (PIT) technique combined with the self-propagating high-temperature synthesis (SHS) method in an unsealed furnace. The analysis includes the studies of the sample microstructure, phase composition, critical transition temperature Tc and critical current density Jc. The experiments show that the PIT technique combined with the SHS method is effective in reducing the Mg volatilization and oxidation. There is little reaction between Mg and Cu in the SHS process, but with the MgCu2 and CuO phases, the reaction does occur in the inner sheath wall of the copper tube. The findings also indicate that there is little MgO in the sample. The sample has a very strong flux pinning ability at the low magnetic fields since the TiB2 phase may prevent the growth of MgB2 grains and lead to a favorable effect on grain refinement. The wires exhibit a high critical current density, e.g. 2.7 × 105 A/cm2 in the 1.0 T field at 4.2 K and 1.3 × 105 A/cm2 in the 2.0 T field at 4.2 K.