Paper on Engineering Materials (Glass)
Assignment
On
Engineering Materials (Glass)
Introduction
Glass is a non-crystalline solid material. Glasses are typically brittle, and often optically transparent.
The most prevalent type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, made of about 75% silica (SiO2) plus Na2O, CaO, and several minor additives. Often, the term glass is used in a restricted sense to refer to this specific use.
[pic]
[pic]Roman Cage Cup from the 4th century A.D.
In science, however, the term glass is usually defined in a much wider sense, including every solid that possesses a non-crystalline (i.e. amorphous) structure and that exhibits a glass transition when heated towards the liquid state. In this wider sense, glasses can be made of quite different classes of materials: metallic alloys, ionic melts, aqueous solutions, molecular liquids, and polymers. Of these, polymer glasses (acrylic glass, polyethylene terephthalate) are the most important; for many applications (bottles, eyewear) they are a lighter alternative to traditional silica glasses.
Glasses play an essential role in science and industry. Their chemical, physical, and in particular optical properties make them suitable for applications such as flat glass, container glass, optics and optoelectronics material, laboratory equipment, thermal insulator (glass wool), reinforcement fiber (glass-reinforced plastic, glass fiber reinforced concrete), and glass art (art glass, studio glass).
Glass transition
[pic]
[pic]Glassblowing at temperatures just above the glass transition
Glass transition or vitrification refers to the transformation of a glass-forming liquid into a glass, which usually occurs upon rapid cooling. It is a dynamic phenomenon occurring between two distinct states of matter (liquid and glass), each with different physical properties. Upon cooling through the temperature range of glass transition (a "glass transformation range"), without forming any
On
Engineering Materials (Glass)
Introduction
Glass is a non-crystalline solid material. Glasses are typically brittle, and often optically transparent.
The most prevalent type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, made of about 75% silica (SiO2) plus Na2O, CaO, and several minor additives. Often, the term glass is used in a restricted sense to refer to this specific use.
[pic]
[pic]Roman Cage Cup from the 4th century A.D.
In science, however, the term glass is usually defined in a much wider sense, including every solid that possesses a non-crystalline (i.e. amorphous) structure and that exhibits a glass transition when heated towards the liquid state. In this wider sense, glasses can be made of quite different classes of materials: metallic alloys, ionic melts, aqueous solutions, molecular liquids, and polymers. Of these, polymer glasses (acrylic glass, polyethylene terephthalate) are the most important; for many applications (bottles, eyewear) they are a lighter alternative to traditional silica glasses.
Glasses play an essential role in science and industry. Their chemical, physical, and in particular optical properties make them suitable for applications such as flat glass, container glass, optics and optoelectronics material, laboratory equipment, thermal insulator (glass wool), reinforcement fiber (glass-reinforced plastic, glass fiber reinforced concrete), and glass art (art glass, studio glass).
Glass transition
[pic]
[pic]Glassblowing at temperatures just above the glass transition
Glass transition or vitrification refers to the transformation of a glass-forming liquid into a glass, which usually occurs upon rapid cooling. It is a dynamic phenomenon occurring between two distinct states of matter (liquid and glass), each with different physical properties. Upon cooling through the temperature range of glass transition (a "glass transformation range"), without forming any
References: 1. ^ Robert Doering, Yoshio Nishi (2007). Handbook of semiconductor manufacturing technology. CRC Press. pp. 12–3. ISBN 1574446754. http://books.google.com/?id=PsVVKz_hjBgC&pg=SA12-PA3&dq=semiconductor+failure+microphotograph&cd=5#v=onepage&q=. 2 3. ^ Libermann H. and Graham C., Production of Amorphous Alloy Ribbons and Effects of Apparatus Parameters On Ribbon Dimensions, IEEE Transactions on Magnetics, Vol. 12 (1976) 4 7. ^ Cahn, J.W., Theory of crystal growth and interface motion in crystalline materials, Acta Met, Vol. 8, p. 554 (1960) 8 9. ^ Moynihan, C. et al. in The Glass Transition and the Nature of the Glassy State, Eds. M. Goldstein and R. Simha, Ann. N.Y. Acad. Sci., Vol. 279 (1976) 10 11. ^ Angell, C.A. and Nagel, S.R., J. Phys. Chem., Vol. 100, p. 13200 (1996) 12 13. ^ Stillinger, F., Science, Vol. 267, p. 1935 (1995) 14