Mechanical properties of MgB2 superconducting wires fabricated by internal Mg diffusion process

Abstract

Mechanical properties of MgB2 monocore superconducting wires fabricated by an internal Mg diffusion (IMD) process and a powder-in-tube (PIT) process were investigated. The uniaxial tensile strain dependence of critical current (Ic) and the transverse compressive stress dependence of Ic were investigated at 4.2 K, 10 T. The IMD-processed MgB2 wire showed a large irreversibility tensile strain limit (ϵirr = 0.67%) and transverse compressive stress tolerance of 206 MPa, whereas the PIT-processed wire had 0.51% and 160 MPa. Furthermore, the tensile strain sensitivity of Ic for the IMD-MgB2 wire was smaller than that for the PIT-MgB2 wire. Consequently, mechanical properties of IMD-processed MgB2 superconducting wires are better than those of PIT-processed wires.