Heat-resistant glass
Description
Glass that is dimensionally stable during large heat fluctuations. Four types of heat-resistant glass are: glass borosilicate, glass alumina glass, alkaline-free silica and quartz. Borosilicate glass typically contains silica (81%), oxide boric oxide (13%), soda (4%) with some alumina. It has a very low thermal expansion coefficient and a high softening point (>600C). Examples of borosilicate glass are Pyrex, Duran and Kimax. Alkaline-free silica glass also has high thermal resistance. A normal glass mixture is softened then leached in an acid bath to remove alkalis followed by heating to 1100C to fill voids. This produces a hard glass, such as Vicor, that can be used up to 870C. glass Quartz glass, or pure fused silica, also provides excellent thermal stability.
Synonyms and Related Terms
heat resistant glass; verre rsistant au chaud (Fr.); Duran; Kimex [Owens Illinois]; Pyrex [Corning Glass]; Vicor [Corning Glass]
Authority
- G.S.Brady, G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 361
- Richard S. Lewis, Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993