An alternative and simple manufacturing process was used to produce high-density bulk MgB2 superconducting objects with large dimensions. The process avoided the use of high-pressure apparatus, and involved the reactive infiltration of liquid Mg into B powder pre-forms. By using an appropriate stainless steel container for the reactants, several products of differing shape were obtained, including tubes, cylinders, rings or disks, of dimensions of the order of the tens of cm. The MgB2 material, unlike high temperature oxide superconductors, permitted easy percolation of the supercurrents across grain boundaries. Due to this property, large samples obtained by reactive liquid infiltration exhibited high superconducting characteristics, as demonstrated by transport and magnetic measurements up to 35K. With regard to high-temperature oxide superconductors, MgB2 offered the advantages of a relatively low density (2.4g/cm3), higher mechanical strength and easier processing.

The Reactive Liquid Mg Infiltration Process to Produce Large Superconducting Bulk MgB2 Manufacts. G.Giunchi, G.Ripamonti, T.Cavallin, E.Bassani: Cryogenics, 2006, 46[2-3], 237-42