Magnezyum difüzyon yöntemiyle MgB2 süperiletken tel ve eklemlerin üretimi ve karakterizasyonu

The aim of the thesis study is to design and implement innovative production methods to solve current problems encountered in IMD MgB2 wires, such as unreacted boron clusters and layer, low engineering critical current density (Jce), superconducting core non-uniformity along the wire, and joining difficulties caused by the thin MgB2 ring layer. In the thesis study, designed wires were produced using non-stoichiometric Mg+B tablets (RD-IMD) and triple thin Mg rods (TH-IMD) in addition to the standard IMD (S-IMD) wire production in which Mg rod is centered in the boron powder. Using the RD-IMD method, MgB2 wire was made with a porous structure instead of a large hole in the middle and a dense circular MgB2 layer around this porous structure. In this way, it has been shown that a higher Jce can be achieved compared to the S-IMD wire in self field. With another design called the TH-IMD method, it has been shown that the electrical properties are improved compared to the S-IMD wire by using three thin Mg rod sources in triangular geometry instead of using a central Mg rod. With this design, the length at which magnesium will diffuse into the boron during the heat treatment is reduced, ensuring that Mg spreads evenly throughout the boron layer. Finally, a special filling method designed to be half Mg and half B (H-EMD) was used to make the thin MgB2 ring surface formed in the S-IMD MgB2 wire more effective. It has been demonstrated that the effective MgB2 surface obtained by the H-EMD method contributes to better contact between the superconducting joint bulk and the wire core and to reducing the critical current difference between the superconducting wires and the joint.