Superconducting Properties Comparison of SiC Doped Multifilamentary ${\rm MgB}_{2}$ Wires of Various Sheaths (Cu, Monel, Glidcop) After High Pressure HIP Treatment

Wires with 6 filaments of cores surrounded by a Nb barrier, and Cu, Monel and Glidcop sheath, drawn by Hyper Tech Inc. to diameters of 0.83 mm, have been treated in a Hot Isostatic Pressure process under high Ar pressures. The pressure of the HIP varied in different processes in order to find the optimal sintering conditions to obtain the highest at high magnetic fields. Also a stainless steel sheathed MgB₂ wire has been used for comparison. The effect of sintering under high pressures on transport properties of those wires was measured by means of critical current and pinning forces Fp. The samples of 70 and 20 mm length were measured in parallel and perpendicular magnetic fields, respectively. High magnetic fields, of up to 14 T, were obtained in a Bitter magnet. The microstructure of annealed samples was investigated by SEM analysis.