Grain structure and irreversibility line of a bronze route CuNb reinforced Nb3Sn multifilamentary wire

High-resolution electron backscatter diffraction (EBSD) technique and DC magnetization were used to characterize a Cu-Nb reinforced bronze route Nb3Sn superconducting multifilamentary wire. The results of DC-magnetization show an extended regime of magnetic reversibility in the operational magnetic field-temperature phase diagram. This observation is discussed in terms of microstructure characteristics of the A15 phase such as grain size, grain boundary misorientation angle distribution, tin gradient across the filaments and residual strain, in connection to the literature. (C) 2012 Published by Elsevier B.V. Selection and/or peer-review under responsibility of the Guest Editors.