Interfacial Reactions in Glass–Ceramic‐to‐Metal Seals

Abstract

During the sealing of glass–ceramics to metals, undesirable interfacial reactions may occur between constituents of the glass and diffusing metal species, and any reaction products formed may have serious consequences on the lifetime behavior of seal components. This paper reviews the factors influencing the lifetime behavior of glass–ceramic‐to‐metal systems, with particular emphasis given to the effect that such interfacial reactions can have on the resultant and longer term properties. Steps that can be taken to enhance desirable interfacial reactions and minimize those that are undesirable are highlighted. In addition, in order to aid in the understanding of complex alloy systems, it is of interest to study both the interfacial reactions and diffusion characteristics of simplified systems without the complicating issue of multiple element diffusion. Thus, a preliminary investigation is highlighted in which a lithium zinc silicate glass nucleated with P2O5 has been sealed to high‐purity Fe, Ni, and Cr metals and the resultant diffusion into the glass of each metal monitored as a function of sealing temperature and time. The data generated have been compared with information from multicomponent alloy systems and an attempt has been made to explain the differences noted.