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The extremely low coefficient of thermal expansion, about 5.5 × 10 −7 /K (20–320 °C), accounts for its remarkable ability to undergo large, rapid temperature changes without cracking (see thermal shock). Phosphorescence in fused quartz from an extremely intense pulse of UV light in a flashtube, centered at 170 nm
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.
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, 0.04 Fe 2 O 3
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 ...
Ultra low expansion glass has an coefficient of thermal expansion of about 10 −8 /K at 5–35 °C. [2] It has a thermal conductivity of 1.31 W/(m·°C), thermal diffusion of 0.0079 cm 2 /s, a mean specific heat of 767 J/(kg·°C), a strain point of 890 °C [1634 °F], and an estimated softening point of 1490 °C [2714 °F], an annealing point ...
The material exhibits a particularly low thermal expansion, with a mean value of 0 ± 0.007×10 −6 K −1 within the temperature range of 0 to 50 °C. [22] High 3D homogeneity [22] with few inclusions, bubbles and internal stria. Hardness similar to that of borosilicate glass. High affinity for coatings. Low helium permeability. Non-porous.
Optical glass refers to a quality of glass suitable for the manufacture of optical systems such as optical lenses, prisms or mirrors.Unlike window glass or crystal, whose formula is adapted to the desired aesthetic effect, optical glass contains additives designed to modify certain optical or mechanical properties of the glass: refractive index, dispersion, transmittance, thermal expansion and ...
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]). They are, therefore, less subject to stress caused by thermal expansion and thus less vulnerable to cracking from thermal shock.