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

A recent effort in the telecommunications industry has been the development of a remanent reed, sealed contact (remreed). 1 One problem encountered in this development was an apparent change in the magnetic properties of the Remendur (Fe, Co, V alloy) reed during the glass-to-metal sealing operation. During sealing, the reed can reach peak temperatures in excess of 1050 °C and may be at temperatures in excess of 900 °C for as long as 8 to 10 seconds. Preliminary data supplied to the authors indicated an increase in the coercivity of reeds from the sealing operation, 2 whereas the results of Ivitazawa, Oguma, and Hara showed a 22-percent decrease in coercivity at switch sealing. 3 Therefore, a description of the exact nature of this change and an explanation of the mechanism by which it occurs were sought. Also, information on the possible influence of variations in the time/temperature sealing cycle on the magnitude of this change was considered relevant to determine if improvements could be achieved by such modifications. 997