Zinc contamination from brass upon heat treating a superconducting magnet

摘要

Theoretical calculations predicted that zinc outgassing from brass spacers during a planned heat treatment would likely damage a lab-scale superconducting magnet. This specter was reinforced by a simulated heat treatment, the samples of which were analyzed by gravimetry, metallography, and microprobe chemical analysis. It was found that zinc escaping from the brass could diffuse 80 (mu)m into copper electrical conductors and degrade their conductivity. To avoid this, steel was temporarily substituted for the brass during the heat treatment process.