Glass ceramics: new compositions and uses

Abstract

Glass ceramics, materials prepared by the controlled crystallisation of glasses, have a variety of established uses dependent on their uniform reproducible fine-grain microstructures, absence of porosity and wide-ranging properties which can be tailored by changes in composition and heat treatment. Moreover, during manufacture complex shapes may be produced using standard glass-forming techniques prior to crystallisation and dimensional changes are small. In recent years, new compositions, processing methods and applications have begun to emerge. Among the recent developments considered are new phosphate-based compositions, the use of sol—gel processing, glass ceramic matrix composites, glass ceramics in microelectronics packaging, glass ceramics bonded to metals and as joining media, high-strength and high-toughness materials and machineable compositions.