Title :
The effect of powder metallurgy Cu(Sn) APCs on grain size reduction and flux pinning in Nb/sub 3/Sn wire
Author :
Thieme, C.L.H. ; Rodrigues, E., Jr. ; Foner, S.
Author_Institution :
Plasma Fusion Center, MIT, Cambridge, MA, USA
fDate :
6/1/1995 12:00:00 AM
Abstract :
Cu artificial pinning centers (APCs) measuring 20 or 5 nm across were introduced to Nb/sub 3/Sn and Nb/sub 3/Sn(Ta) wire by means of powder metallurgy. The APCs increased the filament hardness by less than 10%. Stress anneals could be applied without affecting the Cu APC content or morphology. The Cu APCs led to a fine grained Nb/sub 3/Sn, with an average grain size of 18 nm. The critical current over the filament area was 2250-2600 A/mm/sup 2/ at 12 T, virtually similar for the 20 and 5 nm APC wires. The Cu APCs improved reaction kinetics.<>
Keywords :
alloying additions; annealing; critical currents; flux pinning; grain size; multifilamentary superconductors; niobium alloys; powder metallurgy; superconducting materials; tin alloys; 12 T; 18 nm; 20 nm; 5 nm; Cu powder metallurgy; Nb/sub 3/Sn wire; Nb/sub 3/SnCu; Nb/sub 3/SnSn; Sn powder metallurgy; artificial pinning centers; critical current; filament hardness; flux pinning; grain size reduction; reaction kinetics; stress anneals; Annealing; Critical current; Flux pinning; Grain size; Morphology; Niobium; Powders; Stress; Tin; Wire;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
