Automotive Production Engineering; Glasses Somsak Siwadamrongpong 2/2552.
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Transcript of Automotive Production Engineering; Glasses Somsak Siwadamrongpong 2/2552.
Contents
Glass properties Chemical, Physical and Optical properties Glass structure
Automotive glasses Tempered glasses Zoned tempered glasses Laminated Glasses
Automotive glass production
Glass Properties General properties of glasses
High hardness / Brittle Low density compared to high strength Low thermal expansion coefficient Low heat / electrical conductivity High melting point Good chemical resistance / Chemical inert Wide range of optical transmission
Transparent Translucent Opaque
Popular Glasses
Silicate glasses Soda lime silicate Aluminosilicate Borosilicate Phosposilicate
Chalcogenide glasses Fluoride glasses Ceramic Glaze
: Vitreous silica (SiO2)
O
OSi
O
O
OO
Si
O
O
OSi
O
O
OSiO
OO
Si
O
O
OSi
O
• Each Si tetrahedron links to 4 tetrahedra by sharing corner with each other
• All oxygen are presence as bridging oxygen (BO)
Glass structure; silicate
: Binary silicate glass (6SiO2-2Na2O)
O
O-Si
O
ONa+
OO
Si
O
O-
OSi
O
O
OSiO
OO
Si
O
O
OSi
OO-
Na+
O-
Na+
Na+
• Network linkage is broken as entering of network modifier• Non-bridging oxygen (NBO) is initiated and its charge is
compensated with the metal cation
Glass structure; silicate
: Ternary alumino-silicate glass (6SiO2-Al2O3-2Na2O)
O-
Al
O
O O
O
-
Na+
OSi
OO
Si
O
O
O
SiO
O
Si
O
O
OSi
OO
Si
O
O O- Na+
O
Na+Na+Al
O
O O
O
-
• Network consists of Si and Al tetrahedra• Metal cation is compensated by AlO2
- and the excess cation will break the network and compensate with NBO
Glass structure; silicate
2+
2+ 2+
O
Si
Ca
Al
Glass structure; silicate: Ternary alumino-silicate glass (SiO2-Al2O3-CaO) system
Window glasses
for containers for windows74 SiO2, 13 Na2O, 73 SiO2, 14 Na2O,
10.5 CaO, 1.3 Al2O3, 9 CaO, 0.15 Al2O3,
0.3 K2O, 0.2 SO3, 0.03 K2O, 4 MgO,
0.2 MgO, 0.01 TiO2, 0.02 TiO2, 0.1 Fe2O3
0.04 Fe2O3
Viscosity 550-1450°C: 550-1450°C:log(η, Pa·s) = A + B / (T in °C - To) A = -2.309, B = 3922 A = -2.585, B = 4215
To = 291 To = 263
Glass transition temperature, Tg, Cฐ 573 564
Coefficient of thermal expansion,
ppm/K, ~100-300°C
Density at 20°C, g/cm3 2.52 2.53
Refractive index nD at 20°C 1.518 1.52
Young's modulus at 20°C, Gpa 72 74
Shear modulus at 20°C, Gpa 29.8 29.8
Liquidus temperature, Cฐ 1040 1000
Soda-lime glass
Chemical composition, wt%
9 9.5
Properties
Automotive Glasses
Tempered glasses / Zoned tempered glasses Used for side and rare glasses
Laminated glasses Used for front glass
Other glasses UV / IR cut glass Privacy glass Water repelling glass
Tempered glasses
further cooled
tensioncompression
compression
before cooling
hot
surface cooling
hotcooler
cooler
Strength increase 3-5 times of annealed glasses
Glass Production
Raw Materials
Flat Glass
•Tempered Glasses•Laminated Glasses
Sand powder (SiO2), Al2O3, Na2O, CaO, MgO
Floating Technique
For construction, panel automotive and others