Influences of Glass-to-Metal Sealing on the Structure and Magnetic Properties of an Fe/Co/V Alloy

Abstract

Apparent changes in the coercivity and remanence of the magnetic reed material used in the remreed sealed contact were encountered during the glass‐to‐metal sealing operation. By using primarily metallographic observations correlated with magnetic data, it was determined that these changes were due to a modification of the 600°C‐aged microstructure caused by the time/temperature cycle experienced in sealing. The room‐temperature stable precipitates that are developed by the 600°C anneal to produce magnetic hardening are dissolved, and the alloy converts to a two‐phase duplex body‐centered cubic (BCC) microstructure along one‐half to two‐thirds of the reed shank. This produces a substantial increase in coercive force and some decrease in remanence. The structure and properties of the alloy before sealing have little influence on the reaction.

Remreed Switching Networks for No. 1 and No. 1A ESS: Development of a Remanent Reed Sealed Contact

“…3 It was also found that the effects of this heating did not extend into the paddle section, and that there were no changes observed in this portion of the reed. Since the contact characteristics are much more sensitive to the paddle prop erties, the overall effect of the shank changes were relatively small and did not have a serious effect on switching performance of the sealed contact.…”