The Influence of Metal Diffusion and Interfacial Reactions on the Crystallization Behaviour of Glasses Employed in the Manufacture of Glass-Ceramic-to-Metal Seals

摘要

One of the major attributes of glass-ceramics is an ability to tailor their thermal expansion characteristics and this makes them ideal candidates for sealing to a wide variety of metals and alloys; however, during the sealing process, reaction of diffusing metal species with glass constituents may occur, and this can lead to the formation of undesirable phases within the interfacial region. In addition, diffusion of metal species into the bulk glass away from the interface may affect the overall crystallization kinetics and can result in the formation of unwanted crystalline phases which may be detrimental to the lifetime behaviour of a seal component. This contribution outlines and discusses the factors affecting the crystallization behaviour of glasses employed in seal manufacture and describe methods by which undesirable reactions can be alleviated or minimized through effective control of the process parameters and starting glass composition.