Beta 1

Title Manufacturing of MgB2-tapes
Author Benito, Alvaro Pipo
Institution Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
Thesis level Master's thesis
Year 2005
Abstract Since the discovery of high-temperature superconductors in 1986, a large amount of research has gone into the development of superconducting materials and the manufacturing of superconducting tapes. Superconducting tape can carry extremely high current densities compared with conventional conductors. As such, superconductors are expected to be used increasingly for powerful magnets in hospital scanners, coils for energy storage and cables for power transmission. The first experimental cable for power transmission, supplying 150.000 private homes, was installed in Copenhagen in May 2001. Cables like the above mentioned are based on superconducting tape consisting of ceramic fibres (filaments) in a metal matrix. The manufacturing process used to create these tapes is called "Powder-In-Tube" method (PIT). This method involves pouring a ceramic powder into a metal tube, which is drawn into a long thin wire. The wire is then cut into shorter pieces and packed into yet another metal tube. This tube is then drawn into a long multifilament wire with a diameter of approximately 1 mm. Such a wire can contain hundreds filaments. The wire is then rolled flat to form a tape with a cross-section of approximately 4.0x0.2 mm and a length up to 1km. Finally, the tape is heat-treated and pressed to achieve the desired superconducting properties. In January 2001 Japanese researches discovered that the hitherto disregarded and simple material MgB2 was superconducting at 39K. As such, MgB2 is not a true high-temperature superconductor; however its critical temperature is substantially higher than that of traditional low-temperature superconductors. This, combined with other properties, makes MgB2 very promising for superconducting applications. In this work the process parameters for manufacturing MgB2 superconductors have been studied. This work implies: * A study of the annealing requirements to manufacture single filaments * Testing of different multifilament assemblies configurations. * Testing of different reduction/annealing schedules to draw down multifilament wire. The present work contributes to better understanding of the MgB2 superconductor wire drawing process and the behaviour of the implied materials.
Pages 96
Admin Creation date: 2006-06-22    Update date: 2008-01-11    Source: dtu    ID: 187376    Original MXD