glass


glass
an amorphous material with three-dimensional primary atomic bonding.
Glass can generally be described as an amorphous (non-crystalline) and unstable material having properties dependent on thermal history. Molten hot liquid material is cooled from an elevated temperature to form glass. In the supercooled (metastable) region, the liquid is in an "equilibrium" structure due to the increased viscosity of the material. The liquid is not able to reorganize according to the temperature in a given amount of time. There is a region where the material goes from liquid-like to solid-like. This is the glass transformation range. The material falls out of metastable equilibrium. Crystallization of the material disqualifies it from being a glass. In a single component system, the nucleation rate for a crystal phase increases as undercooling (Tm-T) increases. The growth of nuclei is governed by diffusion, and as the temperature decreases diffusion decreases. The rate of crystallization equals the product of the rate of nucleation and growth rate. Families of glasses: - vitreous silica; - soda lime silicate; - borosilicate; - lead silicate; - alumino silicate; - heavy metal fluoride; - chalcogenide

Mechanics glossary. 2013.

Look at other dictionaries:

  • glass — glass …   Dictionnaire des rimes

  • Glass — (gl[.a]s), n. [OE. glas, gles, AS. gl[ae]s; akin to D., G., Dan., & Sw. glas, Icel. glas, gler, Dan. glar; cf. AS. gl[ae]r amber, L. glaesum. Cf. {Glare}, n., {Glaze}, v. t.] [1913 Webster] 1. A hard, brittle, translucent, and commonly… …   The Collaborative International Dictionary of English

  • GLASS —    Glass results from the heating of a mixture of sand, lime, and sodium carbonate to a very high temperature. When different materials are added to the sand, glass can become transparent, translucent, or colored. While the origins of glass are… …   Historical Dictionary of Architecture

  • Glass — oder Glaß ist der Familienname folgender Personen: Andrea Glass (* 1976), deutsche Tennisspielerin Bernhard Glass (* 1957), deutscher Rennrodler Carter Glass (1858−1946), US amerikanischer Politiker Frank Glaß (* 1965), deutscher Fußballspieler… …   Deutsch Wikipedia

  • glass — [ glæs ] noun *** ▸ 1 clear substance ▸ 2 for drinking out of ▸ 3 objects made of glass ▸ 4 mirror ▸ 5 barometer ▸ + PHRASES 1. ) uncount a hard clear substance used for making objects such as windows or bottles: car windows made of bulletproof… …   Usage of the words and phrases in modern English

  • glass — O.E. glæs glass, a glass vessel, from W.Gmc. *glasam (Cf. O.S. glas, M.Du., Du. glas, Ger. Glas, O.N. gler glass, looking glass, Dan. glar), from PIE *ghel to shine, glitter (Cf. L. glaber smooth, bald, O.C.S. gladuku …   Etymology dictionary

  • GLASS (P.) — GLASS PHILIP (1937 ) Le compositeur américain Philip Glass naît le 31 janvier 1937 à Baltimore. Son père, disquaire et réparateur de radio, initie le jeune Philip à la musique en lui faisant écouter de nombreux disques. À l’âge de huit ans, il… …   Encyclopédie Universelle

  • glass — [ glas ] n. m. • 1628 glace; all. Glas, glass 1886 d apr. l angl. ♦ Arg. Vieilli Verre (d une boisson alcoolisée). Des glass. ⊗ HOM. Glace. ⇒GLASS, subst. masc. Pop. Verre à boire : • POTIRON. C est moi qui fais le chef d orchestre. VANDERAGUE.… …   Encyclopédie Universelle

  • glass — [glas, gläs] n. [ME glas < OE glæs, akin to Ger glas < IE base * ĝhel , to shine > GOLD, GLINT, GLOW] 1. a hard, brittle substance made by fusing silicates with soda or potash, lime, and, sometimes, various metallic oxides into a molten… …   English World dictionary

  • glass´i|ly — glass|y «GLAS ee, GLAHS », adjective, glass|i|er, glass|i|est, noun, plural glass|ies. –adj. 1. like glass; smooth; easily seen through: » …   Useful english dictionary

  • glass|y — «GLAS ee, GLAHS », adjective, glass|i|er, glass|i|est, noun, plural glass|ies. –adj. 1. like glass; smooth; easily seen through: » …   Useful english dictionary


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