Mechanical properties of MgB2superconducting wires fabricated by internal Mg diffusion process

Mechanical properties of MgB 2 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 ( I c ) and the transverse compressive stress dependence of I c were investigated at 4.2 K, 10 T. The IMD-processed MgB 2 wire showed a large irreversibility tensile strain limit ( irr = 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 I c for the IMD-MgB 2 wire was smaller than that for the PIT-MgB 2 wire. Consequently, mechanical properties of IMD-processed MgB 2 superconducting wires are better than those of PIT-processed wires.