A sphere manufactured by NASA out of fused quartz for use in a gyroscope in the Gravity Probe B experiment. It is one of the most accurate spheres ever created by humans, differing in shape from a perfect sphere by no more than 40 atoms of thickness. It is thought that only neutron stars are smoother.

Fused quartz and fused silica are types of glass containing primarily silica in amorphous (non-crystalline) form. They are manufactured using several different processes. Image File history File links Download high-resolution version (1893x1245, 162 KB)-- One of the most perfect spheres ever created by humans. ... Image File history File links Download high-resolution version (1893x1245, 162 KB)-- One of the most perfect spheres ever created by humans. ... This article is about the American space agency. ... Gravity Probe B with solar panels folded Gravity Probe B (GP-B) is a satellite-based mission which launched in 2004. ... This article is about the celestial body. ... This article is about the material. ... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... Wax and paraffin are amorphous. ... For other uses, see Crystal (disambiguation). ...

Fused quartz is made by melting high-purity naturally occurring quartz crystal at around 2000°C using either an electrically heated furnace (electrically fused) or a gas/oxygen-fuelled furnace (flame fused). Fused quartz is normally transparent. For other uses, see Quartz (disambiguation). ...

Fused quartz can also form naturally. The naturally occurring form of fused quartz is usually referrred to as Metaquartzite and is formed under metamorphic conditions. Due to increased heat the crystals within the quartz become fused together. Metaquartzite is formed by the recrystallisation of Quartz under metamorphic conditions. ...

Fused silica is produced using high purity silica sand as the feedstock, and is normally melted using an electric furnace, resulting in a material that is translucent or opaque. (This opacity is caused by very small air bubbles trapped within the material.)

Synthetic fused silica is made from a silicon-rich chemical precursor usually using a continuous flame hydrolysis process which involves chemical gasification of silicon, oxidation of this gas to silicon dioxide, and thermal fusion of the resulting dust (although there are alternative processes). This results in a transparent glass with an ultra-high purity and improved optical transmission in the deep ultraviolet. One common method involves adding silicon tetrachloride to a hydrogen-oxygen flame. Not to be confused with Silicone. ... Hydrolysis is a chemical reaction or process in which a chemical compound reacts with water. ... For the water carbonator, see Gasogene. ... The most fundamental reactions in chemistry are the redox processes. ... For other uses, see Ultraviolet (disambiguation). ... Silicon tetrachloride (SiCl4) is a colourless volatile liquid compound of silicon and chlorine. ...

Fumed silica is manufactured by a similar flame hydrolysis process to synthetic fused silica, however it is in the form of a fine powder/dust and is typically used in applications such as fillers for rubbers and plastics, coatings, adhesives, cements, sealants, cosmetics, pharmaceuticals, inks and abrasives.

The optical and thermal properties are superior to those of other types of glass due to its purity (or rather, its lack of impurities). For these reasons, it finds use in situations such as semiconductor fabrication and laboratory equipment. It has better ultraviolet transmission than most other glasses, and so is used to make lenses and other optics for the ultraviolet spectrum. Its low coefficient of thermal expansion also makes it a useful material for precision mirror substrates. A semiconductor is a solid whose electrical conductivity is in between that of a conductor and that of an insulator, and can be controlled over a wide range, either permanently or dynamically. ... For other uses, see Ultraviolet (disambiguation). ... This article is about the optical device. ... During heat transfer, the energy that is stored in the intermolecular bonds between atoms changes. ... A mirror, reflecting a vase. ...

Chemistry

Fused quartz is a noncrystalline form of silicon dioxide (SiO₂), which is also called silica. (The crystalline form of this material is quartz). R-phrases R42 R43 R49 S-phrases S22 S36 S37 S45 S53 Flash point non-flammable Supplementary data page Structure and properties n, εr, etc. ... Not to be confused with Silicone. ... General Name, symbol, number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, period, block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... For other uses, see Quartz (disambiguation). ...

Applications

Specially prepared fused silica is also the key starting material used to make optical fiber for telecommunications. Optical fibers An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length by confining as much light as possible in a propagating form. ...

Because of its strength and high melting point (compared to ordinary glass), fused silica is used as the envelope of halogen lamps, which must operate at a high envelope temperature to achieve their combination of high brightness and long life. This article is about the material. ... “Light bulb” redirects here. ...

The combination of strength, thermal stability, and UV transparency makes it an excellent substrate for projection masks for photolithography. Photolithography is a process used in semiconductor device fabrication to transfer a pattern from a photomask (also called reticle) to the surface of a substrate. ...

Due to the thermal stability and composition it is used in the semiconductor fabrication furnaces.

Fused quartz has nearly ideal properties for fabricating first surface mirrors such as those used in telescopes. The material behaves in a predictable way and allows the optical fabricator to put a very smooth polish onto the surface and produce the desired figure with fewer testing iterations. A mirror, reflecting a vase. ... This article does not cite any references or sources. ...

Fused silica as an industrial raw material is used to make various refractory shapes such as crucibles, trays, shrouds, and rollers for many high temperature thermal processes including steel making, foundries, and glass manufacture. Refractory shapes made from fused silica have excellent thermal shock resistance and are chemically inert to most elements and compounds including virtually all acids, regardless of concentration. Translucent fused silica tubes are commonly used to sheathe electric elements in room heaters, industrial furnaces and other similar applications.

Physical properties

The extremely low coefficient of thermal expansion accounts for its remarkable ability to undergo large, rapid temperature changes without cracking (see thermal shock). Thermal shock and thermal loading refer to the disfuntion (and perhaps, crack) of a material due to the heating, especially non-stationary and non-uniform. ...

"UV grade" synthetic fused silica (sold under various tradenames including "HPFS", "Spectrosil" and "Suprasil") has a very low metallic impurity content making it transparent deeper into the ultraviolet. An optic with a thickness of 1cm will have a transmittance of about 50% at a wavelength of 170 nm, which drops to only a few percent at 160 nm. However, its infrared transmission is limited by strong water absorptions at 2.2 μm and 2.7 μm. Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ... For other uses, see Wavelength (disambiguation). ... For other uses, see Infrared (disambiguation). ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ...

"IR grade" fused quartz (tradenames "Infrasil", "Vitreosil IR" and others) which is electrically fused, has a greater presence of metallic impurities, limiting its UV transmittance wavelength to around 250 nm, but a much lower water content, leading to excellent infrared transmission up to 3.6 μm wavelength. All grades of transparent fused quartz/fused silica have near-identical physical properties.

The water content (and therefore infrared transmission of fused quartz and fused silica) is determined by the manufacturing process. Flame fused material always has a higher water content due to the combination of the hydrocarbons and oxygen fuelling the furnace forming hydroxyl [OH] within the material. An IR grade material typically has an [OH] content of <10 parts per million.

Optical properties

Dispersion of fused silica can be approximated by the following Sellmeier equation (Malitson 1965): A plot of the refractive index vs. ...

where

and wavelength is measured in micrometers.

Typical properties of clear fused silica

• Density: 2.203 g/cm³
• Hardness: 5.3–6.5 (Mohs Scale)
• Tensile strength: 48.3 MPa
• Compressive strength: >1.1 GPa
• Bulk modulus: ~37 GPa
• Rigidity modulus: 31 GPa
• Young's modulus: 71.7 GPa
• Poisson's ratio: 0.16
• Lame elastic constants: λ=15.872 GPa, μ=31.261 GPa
• Coefficient of thermal expansion: 5.5×10^-7 cm/(cm·K) (average from 20 °C to 320 °C)
• Thermal conductivity: 1.3 W/(m·K)
• Heat capacity: 45.3 J/mol
• Softening point: c. 1665 °C
• Annealing point: c. 1140 °C
• Strain point: 1070 °C
• Electrical resistivity: >10¹⁸ Ω×m
• Dielectric constant: 3.75 at 20 °C 1 MHz
• Dielectric loss factor: less than 0.0004 at 20 °C 1 MHz
• Index of refraction: at 587.6 nm (n_d): 1.4585
• Strain-optic coefficients: p₁₁=0.113, p₁₂=0.252.

For other uses, see Density (disambiguation). ... This article or section does not cite any references or sources. ... This article or section does not cite any references or sources. ... Tensile strength isthe measures the force required to pull something such as rope, wire, or a structural beam to the point where it breaks. ... The megapascal, symbol MPa is an SI unit of pressure. ... Compressive strength is the capacity of a material to withstand axially directed pushing forces. ... The gigapascal, symbol GPa is an SI unit of pressure. ... The bulk modulus (K) of a substance essentially measures the substances resistance to uniform compression. ... In solid mechanics, Youngs modulus (E) is a measure of the stiffness of a given material. ... Figure 1: Rectangular specimen subject to compression, with Poissons ratio circa 0. ... During heat transfer, the energy that is stored in the intermolecular bonds between atoms changes. ... In physics, thermal conductivity, k, is the intensive property of a material that indicates its ability to conduct heat. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... For other uses, see Annealing. ... During cooling, glasses (and quartz, and. ... // Headline text POOP!! Danny Hornsby (also known as Gnome) is a measure indicating how strongly a Gnome can opposes the flow of electric current. ... The relative dielectric constant of a material under given conditions is a measure of the extent to which it concentrates electrostatic lines of flux. ... The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. ...

See also

• Quartz
• Silica (fused silica hardness = 8-10 GPa)
• Vycor
• Aqua aura
• Glass

• List of minerals

For other uses, see Quartz (disambiguation). ... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... Vycor is a glass made by Corning. ... There are very few or no other articles that link to this one. ... This article is about the material. ... Gem animals. ...

External links

• Saint-Gobain Quartz Manufacturer of fused quartz and fused silica materials and products with downloadable data sheets in the Library

• Fused silica contains a list of commercially available fused silica glasses

References

• Malitson, I.H. "Interspecimen Comparison of the Refractive Index of Fused Silica," Journal of the Optical Society of America 55, no. 10 (October 1965): 1205-1209