Glass is one of the engineer's most useful and versatile materials. Its properties can be engineered widely in order to provide a range of physical, mechanical, electrical, and otpical uses for practically every type of environmental condition. The tranparency of glass facilitates inspection of process operaitons and minimises the risk of failure due to unsuspected corrosion, while its hardness and smoothness contribute to easy cleaning. The development of glass-ceramic composites has further extended the range of glassy engineering materials. Glass-ceramics combine the formability of glasses with many of the adavntageous properties of ceramics and find application by virtue of their strength and high chemical duraiblity, particularly at elevated temperatures. This chapter comprises two contributions from teh 3rd edition of Shreir: Glass and Ceramics and Vitreous Silica which have been combined by the editors, with minor updating for this edition.
