Abstract
Effect of metal powder addition on the transport current and strain performance of ex-situ processed MgB_2 tapes with Ni sheath has been studied. The addition of low melting point metal powder, e.g. In and Sn, produces an appreciable increase in the Jc of MgB_2 core. The 10vol% In addition enhances Jc by a factor of 6-7 after the combination of the rolling and the annealing at 200℃. The 10vol% Sn addition enhances Jc by a factor of 〜3. Both of In and Sn metal impregnate into gaps among MgB_2 grains improving the linkage of the grains. The current may transfer through the impregnated metal by the proximity effect. Furthermore, the In and Sn addition improves appreciably the strain tolerance of the MgB_2 tapes.
