Англо-русский перевод BOROSILICATE GLASS

29.10.2018 0 Автор: admin1

Trade names

Borosilicate glass is offered in slightly different compositions under different trade names:

  • Borofloat of Schott AG, a borosilicate glass, which is produced to flat glass in a float process.
  • BK7 of Schott, a borosilicate glass with a high level of purity. Main use in lens and mirrors for laser, cameras and telescopes.
  • Duran of DURAN Group, similar to Pyrex, Simax or Jenaer Glas.
  • Fiolax of Schott, mainly used for containers for pharmaceutical applications.
  • Ilmabor of TGI  (2014 insolvency), mainly used for containers and equipment in laboratories and medicine.
  • Jenaer Glas of Zwiesel Kristallglas, formerly Schott AG. Mainly used for kitchenware.
  • Rasotherm of VEB Jenaer Glaswerk Schott & Genossen, for technical glass
  • Willow Glass is an alkali free, thin and flexible borosilicate glass of Corning

Trade namesedit

Borosilicate glass is offered in slightly different compositions under different trade names:

  • Borofloat of Schott AG, a borosilicate glass, which is produced to flat glass in a float process.
  • BK7 of Schott, a borosilicate glass with a high level of purity. Main use in lens and mirrors for laser, cameras and telescopes.
  • Duran of DURAN Group, similar to Pyrex, Simax or Jenaer Glas.
  • Fiolax of Schott, mainly used for containers for pharmaceutical applications.
  • Ilmabor of TGI  (2014 insolvency), mainly used for containers and equipment in laboratories and medicine.
  • Jenaer Glas of Zwiesel Kristallglas, formerly Schott AG. Mainly used for kitchenware.
  • Rasotherm of VEB Jenaer Glaswerk Schott & Genossen, for technical glass
  • Willow Glass is an alkali free, thin and flexible borosilicate glass of Corning

InLampworking

Borosilicate, or «boro» as it is often referred to, is used
extensively in the glass blowing process lampworking, which involves using a burner
torch to melt and form glass, using a variety of metal and graphite
tools. Borosilicate is referred to as «hard glass» and has a higher
melting point than «soft glass» which is used in glass blowing
formed in large furnaces and large rods. Raw glass used in
lampworking comes in glass rods for solid work and glass tubes for
hollow work tubes and vessels/containers. Lampworking is used to
make complex and custom scientific apparatus; most major
universities have a lampworking shop to manufacture and repair
their glassware. For this kind of «scientific glassblowing,» the
specifications must be exact and the glass blower must be highly
skilled and precise. Lampworking is also done as art and common
items made include goblets, paper weights and pendants.
Borosilicate often has a more three dimensional and exotic look
than soft glass, with natural and multicolored tones to it. Colors
in glass come from combining different amounts of elements,
including cobalt, iron, and silver.

History

Borosilicate glass was first developed by the German glassmaker Otto Schott in the late 19th century. Otto Schott was also the founder of today’s Schott AG, which has sold borosilicate glass later under the brand name DURAN. As part of an equity carve-out in 2005, the DURAN Group was founded and the manufacture of Duran was transferred to it. After Corning Glass Works introduced Pyrex in 1915, the name became synonymous for borosilicate glass in the English-speaking world (though, in reality, a sizable portion of the glass produced under the Pyrex brand has also been made of soda-lime glass since the 1940s). However, borosilicate glass is the name of a glass family with various members tailored to completely different purposes. Most common today is borosilicate 3.3 glass such as Duran, International Cookware’s NIPRO BSA 60, and BSC 51.

In addition to quartz, sodium carbonate, and aluminium oxide traditionally used in glassmaking, boron is used in the manufacture of borosilicate glass. The composition of low-expansion borosilicate glass, such as those laboratory glasses mentioned above, is approximately 80% silica, 13% boric oxide, 4% sodium oxide and 2–3% aluminium oxide. Though more difficult to make than traditional glass due to the high melting temperature required, it is economical to produce. Its superior durability, chemical and heat resistance finds use in chemical laboratory equipment, cookware, lighting, and in certain kinds of windows.

History

Borosilicate glass was first developed by the German glassmaker Otto Schott in the late 19th century. Otto Schott was also the founder of today’s Schott AG, which has sold borosilicate glass later under the brand name DURAN. As part of an equity carve-out in 2005, the DURAN Group was founded and the manufacture of Duran was transferred to it. After Corning Glass Works introduced Pyrex in 1915, the name became synonymous for borosilicate glass in the English-speaking world (though, in reality, a sizable portion of the glass produced under the Pyrex brand has also been made of soda-lime glass since the 1940s). However, borosilicate glass is the name of a glass family with various members tailored to completely different purposes. Most common today is borosilicate 3.3 glass such as Duran, International Cookware’s NIPRO BSA 60, and BSC 51.

In addition to quartz, sodium carbonate, and aluminium oxide traditionally used in glassmaking, boron is used in the manufacture of borosilicate glass. The composition of low-expansion borosilicate glass, such as those laboratory glasses mentioned above, is approximately 80% silica, 13% boric oxide, 4% sodium oxide and 2–3% aluminium oxide. Though more difficult to make than traditional glass due to the high melting temperature required, it is economical to produce. Its superior durability, chemical and heat resistance finds use in chemical laboratory equipment, cookware, lighting, and in certain kinds of windows.

History

Borosilicate glass was first developed by German glassmaker Otto Schott in the late
19th century
and sold under the brand name «Duran» in 1893. After Corning Glass Works introduced Pyrex in 1915, it became a synonym
for borosilicate glass in the English-speaking world.

The European manufacturer of Pyrex, Arc International, uses
borosilicate glass in its Pyrex glass kitchen products;
however, the U.S. manufacturer of Pyrex kitchenware uses tempered
soda-lime
glass. Thus
Pyrex can refer to either soda-lime glass or borosilicate glass
when discussing kitchen glassware, while Pyrex, Duran and Kimax all
refer to borosilicate glass when discussing laboratory
glassware.

Most borosilicate glass is colorless. Colored borosilicate, for
the art glass trade, was first widely brought onto the market in
1986 when Paul Trautman founded Northstar Glassworks. There are now
a number of small companies in the U.S. and abroad that manufacture
and sell colored borosilicate glass for the art glass market.

In addition to the quartz,
sodium
carbonate, and calcium carbonate traditionally used
in glassmaking, boron is used in
the manufacture of borosilicate glass. Typically, the resulting
glass composition is about 70% silica, 10% boron oxide, 8% sodium oxide, 8% potassium
oxide, and 1% calcium oxide (lime). Though somewhat
more difficult to make than traditional glass (Corning conducted a
major revamp of their operations to make it), it is economical to
produce; its superior durability, chemical and heat resistance
finds excellent use in chemical laboratory equipment, cookware, lighting
and, in certain cases, windows.

Physical characteristics

Among the characteristic properties of this glass family are:

  • Different borosilicate glasses cover a wide range of different thermal expansions, enabling direct seals with various metals and alloys like molybdenum glass with a CTE of 4,6, tungsten with a CTE around 4,0 and Kovar with a CTE around 5,0 because of the matched CTE with the sealing partner
  • Allowing high maximum temperatures of typically about 500 °C (932 °F)
  • Showing an extremely high chemical resistance in corrosive environments. Norm tests for example for acid resistance create extreme conditions and reveal very low impacts on glass

The softening point (temperature at which viscosity is approximately 107.6poise) of type 7740 Pyrex is 820 °C (1,510 °F).

Borosilicate glass is less dense (about 2.23 g/cm3) than typical soda-lime glass due to the low atomic mass of boron. Its mean specific heat capacity at constant pressure (20–100 °C) is 0.83 J/(g⋅K), roughly one fifth of water’s.

The temperature differential that borosilicate glass can withstand before fracturing is about 165 °C (329 °F). This compares well with soda lime glass, which can withstand only a 37 °C (99 °F) change in temperature and is why typical kitchenware made from traditional soda-lime glass will shatter if a vessel containing boiling water is placed on ice, but Pyrex or other borosilicate laboratory glass will not.

Optically, borosilicate glasses are crown glasses with low dispersion (Abbe numbers around 65) and relatively low refractive indices (1.51–1.54 across the visible range).

Glass families

For the purposes of classification, borosilicate glass can be roughly arranged in the following groups, according to their oxide composition (in mass fractions). Characteristic of borosilicate glasses is the presence of substantial amounts of silica (SiO2) and boric oxide (B2O3, >8%) as glass network formers. The amount of boric oxide affects the glass properties in a particular way. Apart from the highly resistant varieties (B2O3 up to a maximum of 13%), there are others that – due to the different way in which the boric oxide is incorporated into the structural network – have only low chemical resistance (B2O3 content over 15%). Hence we differentiate between the following subtypes.

Non-alkaline-earth borosilicate glass (borosilicate glass 3.3)

The B2O3 content for borosilicate glass is typically 12–13% and the SiO2 content over 80%. High chemical durability and low thermal expansion (3.3 × 10−6 K−1) – the lowest of all commercial glasses for large-scale technical applications – make this a multitalented glass material. High-grade borosilicate flat glasses are used in a wide variety of industries, mainly for technical applications that require either good thermal resistance, excellent chemical durability, or high light transmission in combination with a pristine surface quality. Other typical applications for different forms of borosilicate glass include glass tubing, glass piping, glass containers, etc. especially for the chemical industry.

Alkaline-earth-containing borosilicate glasses

In addition to about 75% SiO2 and 8–12% B2O3, these glasses contain up to 5% alkaline earths and alumina (Al2O3). This is a subtype of slightly softer glasses, which have thermal expansions in the range (4.0–5.0) × 10−6 K−1.

High-borate borosilicate glasses

Glasses containing 15–25% B2O3, 65–70% SiO2, and smaller amounts of alkalis and Al2O3 as additional components have low softening points and low thermal expansion. Sealability to metals in the expansion range of tungsten and molybdenum and high electrical insulation are their most important features. The increased B2O3 content reduces the chemical resistance; in this respect, high-borate borosilicate glasses differ widely from non-alkaline-earth and alkaline-earth borosilicate glasses. Among these are also borosilicate glasses that transmit UV light down to 180 nm, which combine the best of the borosilicate glass and the quartz world.

In lampworking

Borosilicate (or «boro», as it is often called) is used extensively in the glassblowing process lampworking; the glassworker uses a burner torch to melt and form glass, using a variety of metal and graphite tools to shape it. Borosilicate is referred to as «hard glass» and has a higher melting point (approximately 3,000 °F / 1648 °C) than «soft glass», which is preferred for glassblowing by beadmakers. Raw glass used in lampworking comes in glass rods for solid work and glass tubes for hollow work tubes and vessels/containers. Lampworking is used to make complex and custom scientific apparatus; most major universities have a lampworking shop to manufacture and repair their glassware. For this kind of «scientific glassblowing», the specifications must be exact and the glassblower must be highly skilled and able to work with precision. Lampworking is also done as art, and common items made include goblets, paper weights, pipes, pendants, compositions and figurines.

In 1968, English metallurgist John Burton brought his hobby of hand-mixing metallic oxides into borosilicate glass to Los Angeles. Burton began a glass workshop at Pepperdine College, with instructor Margaret Youd. A few of the students in the classes, including Suellen Fowler, discovered that a specific combination of oxides made a glass that would shift from amber to purples and blues, depending on the heat and flame atmosphere. Fowler shared this combination with Paul Trautman, who formulated the first small-batch colored borosilicate recipes. He then founded Northstar Glassworks in the mid-1980s, the first factory devoted solely to producing colored borosilicate glass rods and tubes for use by artists in the flame. Trautman also developed the techniques and technology to make the small-batch colored boro that is used by a number of similar companies.

Beadmaking

In recent years, with the resurgence of lampworking as a technique to make handmade glass beads, borosilicate has become a popular material in many glass artists’ studios. Borosilicate for beadmaking comes in thin, pencil-like rods. Glass Alchemy, Trautman Art Glass, and Northstar are popular manufacturers, although there are other brands available. The metals used to color borosilicate glass, particularly silver, often create strikingly beautiful and unpredictable results when melted in an oxygen-gas torch flame. Because it is more shock-resistant and stronger than soft glass, borosilicate is particularly suited for pipe making, as well as sculpting figures and creating large beads. The tools used for making glass beads from borosilicate glass are the same as those used for making glass beads from soft glass.

In lampworking

Borosilicate (or «boro», as it is often called) is used extensively in the glassblowing process lampworking; the glassworker uses a burner torch to melt and form glass, using a variety of metal and graphite tools to shape it. Borosilicate is referred to as «hard glass» and has a higher melting point (approximately 3,000 °F / 1648 °C) than «soft glass», which is preferred for glassblowing by beadmakers. Raw glass used in lampworking comes in glass rods for solid work and glass tubes for hollow work tubes and vessels/containers. Lampworking is used to make complex and custom scientific apparatus; most major universities have a lampworking shop to manufacture and repair their glassware. For this kind of «scientific glassblowing», the specifications must be exact and the glassblower must be highly skilled and able to work with precision. Lampworking is also done as art, and common items made include goblets, paper weights, pipes, pendants, compositions and figurines.

In 1968, English metallurgist John Burton brought his hobby of hand-mixing metallic oxides into borosilicate glass to Los Angeles. Burton began a glass workshop at Pepperdine College, with instructor Margaret Youd. A few of the students in the classes, including Suellen Fowler, discovered that a specific combination of oxides made a glass that would shift from amber to purples and blues, depending on the heat and flame atmosphere. Fowler shared this combination with Paul Trautman, who formulated the first small-batch colored borosilicate recipes. He then founded Northstar Glassworks in the mid-1980s, the first factory devoted solely to producing colored borosilicate glass rods and tubes for use by artists in the flame. Trautman also developed the techniques and technology to make the small-batch colored boro that is used by a number of similar companies.

Beadmaking

In recent years, with the resurgence of lampworking as a technique to make handmade glass beads, borosilicate has become a popular material in many glass artists’ studios. Borosilicate for beadmaking comes in thin, pencil-like rods. Glass Alchemy, Trautman Art Glass, and Northstar are popular manufacturers, although there are other brands available. The metals used to color borosilicate glass, particularly silver, often create strikingly beautiful and unpredictable results when melted in an oxygen-gas torch flame. Because it is more shock-resistant and stronger than soft glass, borosilicate is particularly suited for pipe making, as well as sculpting figures and creating large beads. The tools used for making glass beads from borosilicate glass are the same as those used for making glass beads from soft glass.

Physical characteristicsedit

Among the characteristic properties of this glass family are:

  • Different borosilicate glasses cover a wide range of different thermal expansions, enabling direct seals with various metals and alloys like molybdenum glass with a CTE of 4,6, tungsten with a CTE around 4,0 and Kovar with a CTE around 5,0 because of the matched CTE with the sealing partner
  • Allowing high maximum temperatures of typically about 500 °C (932 °F)
  • Showing an extremely high chemical resistance in corrosive environments. Norm tests for example for acid resistance create extreme conditions and reveal very low impacts on glass

The softening point (temperature at which viscosity is approximately 107.6poise) of type 7740 Pyrex is 820 °C (1,510 °F).

Borosilicate glass is less dense (about 2.23 g/cm3) than typical soda-lime glass due to the low atomic mass of boron. Its mean specific heat capacity at constant pressure (20–100 °C) is 0.83 J/(g⋅K), roughly one fifth of water’s.

The temperature differential that borosilicate glass can withstand before fracturing is about 165 °C (329 °F). This compares well with soda lime glass, which can withstand only a 37 °C (99 °F) change in temperature and is why typical kitchenware made from traditional soda-lime glass will shatter if a vessel containing boiling water is placed on ice, but Pyrex or other borosilicate laboratory glass will not.

Optically, borosilicate glasses are crown glasses with low dispersion (Abbe numbers around 65) and relatively low refractive indices (1.51–1.54 across the visible range).

Glass familiesedit

For the purposes of classification, borosilicate glass can be roughly arranged in the following groups, according to their oxide composition (in mass fractions). Characteristic of borosilicate glasses is the presence of substantial amounts of silica (SiO2) and boric oxide (B2O3, >8%) as glass network formers. The amount of boric oxide affects the glass properties in a particular way. Apart from the highly resistant varieties (B2O3 up to a maximum of 13%), there are others that – due to the different way in which the boric oxide is incorporated into the structural network – have only low chemical resistance (B2O3 content over 15%). Hence we differentiate between the following subtypes.

Non-alkaline-earth borosilicate glass (borosilicate glass 3.3)edit

The B2O3 content for borosilicate glass is typically 12–13% and the SiO2 content over 80%. High chemical durability and low thermal expansion (3.3 × 10−6 K−1) – the lowest of all commercial glasses for large-scale technical applications – make this a multitalented glass material. High-grade borosilicate flat glasses are used in a wide variety of industries, mainly for technical applications that require either good thermal resistance, excellent chemical durability, or high light transmission in combination with a pristine surface quality. Other typical applications for different forms of borosilicate glass include glass tubing, glass piping, glass containers, etc. especially for the chemical industry.

Alkaline-earth-containing borosilicate glassesedit

In addition to about 75% SiO2 and 8–12% B2O3, these glasses contain up to 5% alkaline earths and alumina (Al2O3). This is a subtype of slightly softer glasses, which have thermal expansions in the range (4.0–5.0) × 10−6 K−1.

High-borate borosilicate glassesedit

Glasses containing 15–25% B2O3, 65–70% SiO2, and smaller amounts of alkalis and Al2O3 as additional components have low softening points and low thermal expansion. Sealability to metals in the expansion range of tungsten and molybdenum and high electrical insulation are their most important features. The increased B2O3 content reduces the chemical resistance; in this respect, high-borate borosilicate glasses differ widely from non-alkaline-earth and alkaline-earth borosilicate glasses. Among these are also borosilicate glasses that transmit UV light down to 180 nm, which combine the best of the borosilicate glass and the quartz world.

Использование

Художники по стеклу применяют боросиликатное стекло для изготовления различных композиций в пламени горелки. Из него выдуваются дорогостоящие декоративные художественные фужеры, бокалы, вазы, графины, фигурки и т.д. Также из него изготавливают ювелирные украшения, зачастую сочетая с драгоценными металлами.

В быту, для изготовления посуды для открытого огня, заварочных чайников. Применяется как материал для лабораторной посуды, а также для химической промышленности и других отраслей, например, в качестве материала теплообменника для тепловых электростанций. Также применяется для изготовления .

Также боросиликатное стекло может применяться для изготовления для , бластомера, которая проводится для проведения предимплантационной генетической диагностики с использованием в качестве генетического материала биопсийных клеток. Существует 3 варианта пипеток с внутренним диаметром от 4 до 7,5 мкм. Длина пипетки составляет от 60 до 75 мм и имеет угол скоса 30°. Пипетки предназначены для одноразового использования.

Боросиликатные стёкла различных составов составляют значительную часть марок . В частности, к классу боросиликатных относятся такие типы оптических стёкол как лёгкие (ЛК), обычные (К), тяжёлые (ТК) и баритовые кроны (БК), а также кронфлинты (КФ). В свою очередь в каждый из этих типов входят несколько различных марок стёкол, выпускаемых промышленностью.

Из боросиликатного стекла изготавливают не только линзы, но и зеркала для . Причина этого в сочетании цены и малого коэффициента температурного расширения.
В начале XX века это был лучший материал для этих целей. В настоящее время лучшим материалом являются . и , но они стоят дороже пирекса.

Из боросиликатного стекла с коэффициентом линейного теплового расширения 2,8⋅10−6 °C−1 производства фирмы изготавливаются зеркала для (ГМТ).

Боросиликатное стекло

Некоторые боросиликатные стекла обладают свойством постепенно выделять щелочной борат при температурах выше точки превращения. Последний обычно остается в массе стекла в виде мельчайших капелек. Процесс можно провести так, что борат щелочного металла образует отдельную фазу, которую можно удалить выщелачиванием остывшего стекла разбавленной кислотой. По методике Викора изделию из щелочного боросиликатного стекла придают форму при обычной рабочей температуре. Затем его нагревают, выщелачивают, спекают, благодаря чему возникает значительное сжатие, однако первоначальная форма сохраняется.

Некоторые боросиликатные стекла обладают свойством постепенно выделять щелочной борат при температурах выше точки превращения. Последний обычно остается в массе стекла в виде мельчайших капелек. Процесс можно провести так, что борат щелочного металла образует отдельную фазу, которую можно удалить выщелачиванием остывшего стекла разбавленной кислотой. По методике Вико-ра изделию из щелочного боросиликатного стекла придают форму при обычной рабочей температуре. Затем его нагревают, выщелачивают, спекают, благодаря чему возникает значительное сжатие, однако первоначальная форма сохраняется.

Стеклянный насос.

Кроме боросиликатного стекла применяются также различные сорта химически стойких стекол, из которых изготовляется лабораторная посуда и детали химической аппаратуры.

Зависимость вязкости коммерческих стекол от температуры.

Вязкости боросиликатных стекол ( 5, 6 на рис. 1) в интервале обработки достаточно быстро не изменяются.

Припои для электровакуумных приборов с ГПрОГ-450 С.

Ковар и боросиликатное стекло спаивают на полуавтоматах при температурах порядка 1000 — 1080 С. Предварительно производят отжиг ковара в водороде при 1100 С. Сплав хорошо обрабатывается и поддается вытяжке и штамповке. Детали из этого сплава отжигают в вакууме не ниже 10 — 4 мм рт. ст. Перед пайкой их подвергают окислению на воздухе при 350 С до образования на поверхности окисной пленки темно-синего цвета. Пайку производят в атмосфере азота индукционным нагревом. После спаивания узлы отжигают в вакууме при 720 С. Молибден и тугоплавкое стекло спаивают индукционным нагревом в агроне или азоте. Предварительно молибден отжигают в водороде, а затем окисляют на воздухе при 600 С. Образующаяся на поверхности коричневато-фиолетовая пленка двуокиси молибдена Мо02 прочно связывается с металлом и хорошо смачивается стеклом; напротив, трехокись Мо03 ухудшает условия адгезии к стеклу и так как она летуча, то ее после окисления отгоняют в атмосфере аргона при 1000 С. Допустимая для спая Гпгог 700 С. Находит применение также форстеритовая, а в последнее время берил-лиевая керамика.

Зависимость объема стекла от температуры.| Зависимость коэффициента расширения стекла ( 7 и энергии активации ( 2 от температуры.

Было исследовано боросиликатное стекло примерно следующего состава ( в мол.

Колонка из боросиликатного стекла, U-образная, внутренний диаметр 2 мм, заполняется почти до уплотнения впускного устройства.

Колонка из боросиликатного стекла 100 X X 0 3 см, заполненная 2 % НПГС на промытом кислотой хромосорбе W зернения 80 — 100 меш. Температура колонки 41 С в течение 3 мин. С и изотермический режим в течение 15 мин.

При обработке боросиликатных стекол необходимо добавлять к вдуваемому воздуху некоторое количество кислорода.

Температура размягчения боросиликатного стекла составляет 580 — 610 С, безборного малощелочного 725 С. В СССР стеклянные трубы изготовляются из термостойкого безборного малощелочного стекла. Все трубы подвергаются отжигу.

В состав термостойких боросиликатных стекол обычно взамен окиси кальция вводят окись бария.

Список источников

  • www.ngpedia.ru
  • howlingpixel.com
  • www.wikizero.com
  • wiki2.org
  • www.thefullwiki.org
  • en.wikibedia.ru