Title :
Incorporation of stabilizer to rapid-quenched and transformed Nb/sub 3/Al multifilamentary superconductors
Author :
Kosuge, M. ; Takeuchi, T. ; Tagawa, K. ; Banno, N. ; Yuyama, M. ; Wada, H. ; Nakagawa, K. ; Yamanaka, T. ; Moriai, H.
Author_Institution :
Tsukuba Magnet Lab., Nat. Res. Inst. for Metals, Ibaraki, Japan
fDate :
3/1/2000 12:00:00 AM
Abstract :
A Nb/sub 3/Al superconducting conductor based on Jelly-Rolled (JR) Nb/Al composites is fabricated by the rapid-heating and quenching of a wire of such composites with subsequent transformation-annealing to form Nb/sub 3/Al phase. Since the conductor is heated up to 1900/spl deg/C, far above the melting point of Cu, during fabrication, Cu stabilizer cannot directly be included as a basic composite constituent. In the present study, attempts have been made to incorporate the stabilizer to the Nb/sub 3/Al conductor. In a mechanical-cladding method, the as-quenched composite is wrapped longitudinally with a Cu tape, and groove-rolled for mechanical bonding. For internal stabilization, Jelly-Rolled Nb/Al filaments are isolated from the stabilizers by a Nb-filaments barrier and the formation of unwanted Nb-Al-Cu (Ag) compounds are prevented. Ag-stabilizer, little reactive with Nb, can dramatically decrease the Nb-barrier thickness required and allows the increase in the volume fraction of the stabilizer instead.
Keywords :
aluminium alloys; critical current density (superconductivity); multifilamentary superconductors; niobium alloys; rapid thermal processing; type II superconductors; 1900 C; Jelly-Rolled; Nb-filaments barrier; Nb/sub 3/Al; Nb/sub 3/Al multifilamentary superconductors; groove-rolled; internal stabilization; mechanical bonding; rapid-heating; rapid-quenched; stabilizer; transformation-annealing; volume fraction; Bonding; Conductors; Critical current density; Fabrication; High temperature superconductors; Metastasis; Multifilamentary superconductors; Niobium; Superconducting filaments and wires; Superconducting magnets;
Journal_Title :
Applied Superconductivity, IEEE Transactions on