CHANGES OF T-C, J(C) AND STOICHIOMETRY OF NB3SN PHASE FORMED DURING INTERNAL TIN DIFFUSION PROCESS

A multifilamentary wire containing 6660 Nb filaments was manufactured by the internal tin process. Studies on the formation of the Nb3Sn lay ers in relation to T-C, J(C) and conductor morphology are presented. T he results were discussed on the base of microscopic observations of t he development of Cu-Sn phases during multi-stage diffusion processes. Magnetic properties, in correlation with cross-sectional microstructu re were studied in order to define the inter-filamentary bridging duri ng heat treatment.