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Guitar slide made of borosilicate glass. Borosilicate glass is a type of glass with silica and boron trioxide as the main glass-forming constituents. Borosilicate glasses are known for having very low coefficients of thermal expansion (≈3 × 10 −6 K −1 at 20 °C), making them more resistant to thermal shock than any other common glass.
Soda–lime glass (for containers) [2] Borosilicate (low expansion, similar to Pyrex, Duran) Glass wool (for thermal insulation) Special optical glass (similar to Lead crystal) Fused silica Germania glass Germanium selenide glass Chemical composition, wt% 74 SiO 2, 13 Na 2 O, 10.5 CaO, 1.3 Al 2 O 3, 0.3 K 2 O, 0.2 SO 3, 0.2 MgO, 0.01 TiO 2, 0. ...
A number of materials contract on heating within certain temperature ranges; this is usually called negative thermal expansion, rather than "thermal contraction".For example, the coefficient of thermal expansion of water drops to zero as it is cooled to 3.983 °C (39.169 °F) and then becomes negative below this temperature; this means that water has a maximum density at this temperature, and ...
Thermal shock resistance measures can be used for material selection in applications subject to rapid temperature changes. The maximum temperature jump, , sustainable by a material can be defined for strength-controlled models by: [4] [3] = where is the failure stress (which can be yield or fracture stress), is the coefficient of thermal expansion, is the Young's modulus, and is a constant ...
A Pyrex borosilicate glass measuring cup. Borosilicate glasses (e.g. Pyrex, Duran) typically contain 5–13% boron trioxide (B 2 O 3). [75] Borosilicate glasses have fairly low coefficients of thermal expansion (7740 Pyrex CTE is 3.25 × 10 −6 /°C [78] as compared to about 9 × 10 −6 /°C for a typical soda–lime glass [79]).
The manufacturing process for soda–lime glass consists in melting the raw materials, which are the silica, soda (Na 2 O), hydrated lime (Ca(OH) 2), dolomite (CaMg(CO 3) 2, which provides the magnesium oxide), and aluminium oxide; along with small quantities of fining agents (e.g., sodium sulfate (Na 2 SO 4), sodium chloride (NaCl), etc.) in a glass furnace at temperatures locally up to 1675 ...
The coefficient of thermal expansion (CTE) of the processed glass needs to be similar to those of the bonding partner. [2] Anodic bonding can be applied with glass wafers at temperatures of 250 to 400 °C or with sputtered glass at 400 °C. [3] Structured borosilicate glass layers may also be deposited by plasma-assisted e-beam evaporation. [4]
The borosilicate glass of usual laboratory glassware has a lower coefficient of thermal expansion than tungsten, thus it is necessary to use an intermediate sealing glass to get a stress-free seal. There are combinations of glass and iron-nickel-cobalt alloys ( Kovar ) where even the non-linearity of the thermal expansion is matched.