By Topic

Fabrication of Tantalum Sheet for Superconductor Diffusion Barriers

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

7 Author(s)
Balachandran, S. ; Dept. of Mech. Eng., Texas A&M Univ., College Station, TX, USA ; Hartwig, K.T. ; Baars, D.C. ; Mathaudhu, S.N.
more authors

Poor deformation behavior of commercial Ta sheet used for Sn diffusion barriers in multifilamentary Nb3Sn superconductors leads to excessive Ta-Cu interface roughening and the use of a thick Ta layer to overcome layer fracture. The problem stems from three factors: Ta strain hardens faster and to a much higher flow stress than Cu, pure Cu is adjacent to Ta, and the Ta sheet microstructure is non-uniform and non-optimum. The objective of our work is to fabricate Ta sheet with improved deformation behavior over present day commercial Ta sheet. The hypothesis is that a uniform, fine-grained, and well-textured sheet with a preferred orientation will have better codeformation characteristics. To test this thinking, 25 mm square cross-section bars of Ta were deformed by equal channel angular extrusion (ECAE) to strains of nine, sliced in half, annealed to various levels, and rolled to 0.5 mm thick sheet, and Cu-Ta monofilaments fabricated with the processed sheet. Experimental results and roughness measurements on the Ta layers indicate that severe plastic deformation (SPD) processed sheet shows better characteristics than commercial Ta layers. This results from the uniform microstructure and fine grains in precursor Ta sheet processed by SPD.

Published in:

Applied Superconductivity, IEEE Transactions on  (Volume:19 ,  Issue: 3 )