Changes of T/sub c/, J/sub c/ and stoichiometry of Nb/sub 3/Sn 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 Nb/sub 3/Sn layers in relation to T/sub c/, J/sub c/ and conductor morphology are presented. The results were discussed on the base of microscopic observations of the development of Cu-Sn phases during multi-stage diffusion processes. Magnetic properties, in correlation with cross-sectional microstructure were studied in order to define the inter-filamentary bridging during heat treatment.