A systematic experimental study of the variations of superconducting transition temperature and criticalhyphen;current density is reported forinsituformed multifilamentary Cuhyphen;Nb3Sn composites containing 10 at.percnt; Nb and 2ndash;3 at.percnt; Sn annealed at either 650 or 700thinsp;deg;C. A particular emphasis was placed on the evaluation of uniformity, thermal stability, and mechanical strength. Criticalhyphen;current density was measured as a function of transverse magnetic field and was found to increase in samples measured in a bent position. The overall criticalhyphen;current performance is comparable to that of reinforced stabilized conventional composites. Large residual resistivity ratios are indicative of a clean highhyphen;conductivity matrix surrounding each individual filament, an important requirement for thermal stability. High resistance to plastic flow in these composites is attributed to strong filamenthyphen;tohyphen;matrix bonding and small interfilament spacing. The ultimate tensile strength at 77thinsp;deg;K reached a value of sim;100 ksi (690 MPa). The measured uniformity of both critical currents and mechanical properties is found to be consistent with microstructural observations. Finally, an overall comparison is made with conventional continuoushyphen;filament superconducting composites.
展开▼
