Trivalent Chrome Plating for ITER Strands

ITER conductors for Toroidal Field (TF) and Central Solenoid (CS) coils require many strands of and copper with a 1 to 2 micron thin coating of chromium. The purpose of the Cr is two-fold: to keep the strands from sintering during a prolonged high temperature reaction treatment and to offer inter-st...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on applied superconductivity 2012-06, Vol.22 (3), p.7800304-7800304
Main Authors: Kanithi, H., Pyon, T., Lajewski, J., Berglund, D., Bates, C., Smith, D., Scoble, H.
Format: Article
Language:English
Subjects:
Adhesives
Applied sciences
Chromium
Coatings
Copper
Electrical engineering. Electrical power engineering
Electromagnets
Exact sciences and technology
High temperature
International thermonuclear experimental reactor
Niobium-tin
Plating
residual resistivity ratio RRR
Strands
Surface treatment
Texture
Thickness measurement
Toxic
Toxicology
trivalent Cr plating
Various equipment and components
Wire
Wires
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:ITER conductors for Toroidal Field (TF) and Central Solenoid (CS) coils require many strands of and copper with a 1 to 2 micron thin coating of chromium. The purpose of the Cr is two-fold: to keep the strands from sintering during a prolonged high temperature reaction treatment and to offer inter-strand resistance. Up until recently Cr plating is applied using a hexavalent chrome (Cr-VI) electrolytic process. This process is highly toxic and requires expensive and strict environmental and safety controls. No reel-to-reel plating lines are available in the US suitable for plating wire since there has been no need for such plating of commercial wires. Therefore Summit Corp. of America and Luvata Waterbury, Inc. have developed an efficient and economical plating process based on environmentally friendly and less toxic trivalent chrome (Cr-III). We have studied adhesion of Cr to the base copper, its ductility, texture, thermal stability and residual resistivity ratio (RRR) of base copper following the high temperature heat treatment. After detailed evaluation and side-by-side comparison of Cr-III and Cr-VI plating we have successfully qualified the later for the ITER TF strands. The new process has coated over 15 tons of superconductor and Cu strand with stable and predictable performance. Process and performance details will be presented in this paper.
ISSN:1051-8223
1558-2515
DOI:10.1109/TASC.2011.2180499