Mechanical properties of superconducting MgB2 wire

This study aims at examining the mechanical properties of MgB2 wires fabricated with PIT method by studying the effect of tensile and bending stresses on their current carrying capacity. Wires are mounted on a tensile machine and are subjected to different load increments within both the elastic and the plastic regions. The current carrying capacity is measured for each load and the behavior of I-c versus stress/strain is studied. Microstructures of MgB2 core are studied for different loads by using SEM. For bending tests, two cases are examined. The first case is to anneal MgB2 wires then wind them on mandrels with different diameters, while the second case is to wind un-annealed wires on the same mandrels with different diameters then anneal the winded wires. A comparison between both cases is made using SEM for all different diameters and measuring the corresponding Ic. The behavior of I, versus bending strain is studied. This whole study aims at giving a clear picture of the optimum loading, bending and processing conditions at which MgB2 wires will possess a high current carrying capacity for practical applications. (c) 2006 Elsevier B.V. All rights reserved.