LARGE SHAPED PARTS OF MELT CAST BSCCO FOR APPLICATIONS IN ELECTRICAL ENGINEERING

Manufacturing of large HTSC shaped parts is a challenge because most of the known ceramic procedures can not be applied. In the case of HTSC powders the known procedures result in bulk parts with =satisfactory properties. Our Melt Casting Process (MCP) is an alternative route and is tailor made for BSCCO, especially for the 2212 phase. Melt casting offers an easy access to a variety of different shapes and sizes e.g rods and tubes (length up to 800 mm, respectivley 500 mm) or hollow cylinders (O 200 mm). Recently the properties of the material obtained by MCP could significantly be improved by admixing of strontium sulphate (SrSO4). We have already obtained jc-values superior to those of sintered ceramics of YBCO or BSCCO: Jc=55 000 A/cm2 (4 K) and 2200 A/cm(2) (77 K) were achieved without external fields, large bulk parts exhibited more than 2000 A (77 K) in their self field. The pecularities of MCP allow the integrating of noble metal current contacts which exhibit total resistances <= 1 mu ohm (77 K), even under the charge of high currents. First test of prototypes for applications in electrical engineering (rods and tubes for current leads, hollow cylinders for inductive current limiters) show promising results.