Quartz Glasses. Types of Glass. Application. Physical and Chemical Properties. Forms of Product. SEE THE WORLD IN A NEW LIGHT Stand: 2/13

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1 Types of Glass Application Physical and Chemical Properties Forms of Product Stand: 2/13

2 NOTE: All data in this product information brochure are general product specifications and not binding definition of values. We reserve the right to change the data anytime. Therefore we recommend contacting us before processing the product. We cannot guarantee that the usage or processing of this product does not infringe on third parties intellectual property rights. OSRAM GmbH Plant Berlin Nonnendammallee 44 D Berlin Phone / Fax / OSRAM Gesellschaft mit beschränkter Haftung München 2/13 2

3 INHALTSVERZEICHNIS: Introduction and Definitions S. 5 Types of Glass and their application S. 7 Properties and chemical composition S. 9 Production range S. 11 Forms of product S. 12 Glass 401, 402 S. 13 Glass 405, 406, 407 S. 15 Glass 421, 422, 424 S. 17 Glass 451, 452, 454 S. 19 Glass 455, 456 S. 22 Glass 461, 462, 464 S. 24 Glass 471, 472, 474 S. 26 Glass 481, 482 S. 28 2/13 3

4 For many years OSRAM has manufactured different types of glass and has acquired great knowledge and experience in their manufacture and processing. Our quartz glass OVISIL is manufactured as tubing and rods and which are used as envelopes and seals for filament and discharge lamps, lamp mounts or the like. Mass production, especially of lamps, requires rational manufacturing processes and glass products of the highest precision. Constant quality testing guarantees these characteristics. Our quartz glass is melted in small electric furnaces. The flexibility of the manufacturing methods and their economical optimization are of great advantage to the user of these products. The many types of lamps manufactured by OSRAM require quartz glass with various geometrical shapes and physical properties. These types of glass must meet the requirements of the many different types of lamps manufactured by us and in addition must be suitable for many other purposes. OVISIL is available as the following: Machine-drawn tubings and rods Pre-cut tubings and rods A description of OVISIL silicate glasses by OSRAM is available as brochure Silicate Glasses. 2/13 4

5 Physical and chemical properties of glass All data in this catalogue are typical values and not guaranteed boundary values. Depending on the glass type the following properties are specified: Coefficient of Expansion α [10-6 /K -1 ] The values measured as per ISO 7991 between 20 C and 1000 C show the suitability of the glass (with its behavior in the transformation range) for its durable sealing to metals, ceramics and other glasses. Poisson s Ratio µ at 20 C This factor shows the relative diameter decrease in relation to the relative linear expansion measured by the axial tensile load of an elastic rod. It is an important factor for the calculation of elastic behavior of glasses and of the thermal stress factor. Young s Modulus E [GPa] at 20 C This factor is necessary for the conversion of strain to stress, which occurs in glass-to-metal seals as well as for the calculation of the thermal stress factor. Density [g/cm 3 ] at 20 C Measured at 20 C with tension-free samples having no blisters or flaws. Thermal Stress Resistance T σ 8 [K] Shows the difference between the inside temperature and the outer surface temperature of a glass rod after the technically permissible tensile load of σ = 8 N/mm 2. Glass with a higher the thermal shock resistance shows a higher the permissible temperature difference. Transformation Temperature t g [ C] Collected by the dilatometric method according to ISO /13 5

6 Physical and chemical properties of glass Viscosity η [dpa s] The dynamic viscosity of glass is shown with four characteristic values, defined in ISO 7884:-1: a) at 10 14,7 (10 14,5 ) dpa s (strain point) b) at 10 13,2 (10 13,0 ) dpa s (annealing point) c) at 10 7,6 dpa s (softening point) They correspond with the viscosities during which: a) stress in the glass is relieved within a few hours, b) stress in the glass is relieved within a few minutes, c) deformations become evident within a few minutes. The values are measured in balanced state. Viscosity values in time-temperature balance are shown in the diagrams. Resistivity D in solid state The values are given in C at 10 4 ; 10 8 ; Ω cm and in Ω cm at 250 and 350 C. A diagram shows the dependence of the electric resistance on the temperature throughout the range of application of glass. Dielectric Constant ε and Dielectric Loss Factor tan δ Both values are shown for 20 C and 1 MHz. Birefrigence Factor C [10-6 mm 2 /N] This gives the relative wavelength retardation in nm/cm with a sample load of 0,1 N/mm 2, at room temperature and wavelength 540 nm. Optical Refraction Coefficient n d at room temperature The refraction coefficient shown is for the yellow Helium line, measured at room temperature. Chemical resistance [class] These values are determined according to: DIN ISO 719 for hydrolytic resistance (classes 1-5) DIN for acid resistance (classes 1-4) DIN ISO 695 for alkali resistance (classes 1-3) Larger class numbers signify increased solubility. 2/13 6

7 Summary of types OVISIL OVISIL 401, 402 UV absorbing, Cerium doped quartz glass with reduced UV transmission: Typ 401 Typ 402 unbaked approx. 125 ppm OH vacuum baked, 10 ppm Application: Lamp bulbs for filament lamps, e.g. projection lamps automobile headlamps and photographic lamps, jackets for discharge lamps. OVISIL 405, 406, 407 UV absorbing, Cerium doped quartz glass with reduced viscosity: Typ 405 Typ 406 Typ 407 unbaked approx. 70 ppm OH vacuum baked, 4 ppm OH after treated, 20 ppm Application: Lamp bulbs for filament lamps, e.g. projection lamps automobile headlamps and photographic lamps, jackets for discharge lamps. OVISIL 421, 422, 424 UV absorbing, TiO 2 doped quartz glass: In comparison to OVISIL 461, 462 and 464 with improved transmission in long-wave UV and visuable area. Typ 421 Typ 422 Typ 424 unbaked approx. 150 ppm OH vacuum baked, 4 ppm OH vacuum baked, 1 ppm OH Application: Used for arc tubes and sleeve material in high-pressure discharge lamps. The quartz glass reduces the short-wave UV radiation and prevents ozone formation. OVISIL 451, 452, 454 Un-doped quartz glass: Type 451 Type 452 Type 454 not vacuum baked, 150 ppm OH (approx.) vacuum baked, 4 ppm OH vacuum baked, < 1 ppm OH Application: Used for burners and exhaust tubes in high-pressure discharge lamps for street and indoor applications, floodlighting and cosmetic applications. Used for arc- and exhaust tubes in UV-lamps, e.g. germicidal lamps, for halogen incandescent lamps bulbs, e.g. projection lamps, automobile headlamps and photographic lamps. 2/13 7

8 Summary of types OVISIL OVISIL 455, 456 With colourless metal oxides and reduced viscosity: Typ 455 Typ 456 unbaked approx. 75 ppm OH vacuum baked, 4 ppm OH Application: Rods in automobile headlamps. OVISIL 461, 462, 464 UV absorbing, TiO 2 doped quartz glass: Typ 461 Typ 462 Typ 464 unbaked approx. 150 ppm OH vacuum baked, 4 ppm OH vacuum baked, 1 ppm OH Application: Used for arc tubes and sleeve material in high-pressure discharge lamps. The quartz glass reduces the short-wave UV radiation and prevents ozone formation. OVISIL 471, 472, 474 UV absorbing, TiO 2 high doped quartz glass: Typ 471 Typ 472 Typ 474 unbaked approx. 150 ppm OH vacuum baked, 4 ppm OH vacuum baked, 1 ppm OH Application: Burners for therapeutic and reprography high pressure and low pressure discharge lamps. OVISIL 481, 482 Cerium and Titanium doped with reduced UV transmission. Typ 481 Typ 482 unbaked approx. 100 ppm OH vacuum baked, 4 ppm OH Application: UV absorbing quartz glass used for arc tubes in halogen lamps and sleeve material for discharge lamps. UV radiation drastically reduced at approx. 350 nm. 2/13 8

9 Properties of OVISIL glasses overview of typical values Nr. OVISIL Doping OH-content Temperature at viscosity Typical spectral transmission at 1 mm wall thickness at wave length 10 14,7 dpas 10 13,2 dpas 10 7,6 dpas 220 nm 254 nm 315 nm 350 nm [10-6 ] [C] [C] [C] [%] ca ca ,7 0,3 0, ca k.a. k.a k.a. k.a ca < ca ca < ca < ca /13 9

10 Chemical Composition of Quartz Glass OVISIL quartz glass are manufactured of natural raw material a high pure SiO 2 sand, a certain fluctuation margin of natural impurities therefore is inevitable. OVISIL 451, 452 and 454 can also be manufactured in superior grade additionally marked H. In addition to SiO 2 and potential dopants these impurities can be found (values in ppm): Standard Quality: Typical values: Aluminium 16 Iron 1 Magnesium 1 Barium < 1 Potassium 1 Sodium 1,5 Calcium 1 Lithium 1 Titanium 1 H-grade: Typical values: Aluminium 8 Iron 0,5 Magnesium 1 Barium < 1 Potassium 0,5 Sodium 0,5 Calcium 1 Lithium 1 Titanium 1,5 2/13 10

11 Technical Capability Tubing: Tubing length: any length between 10 and 1300 mm Outer diameter and wall thickness: guidline values for the wall thickness of the tubing as a function of the outer diameter as per this graph: Wall thickness [mm] Production range Outer diameter [mm] Tubing at outer diameter range from 2,9 up to approx. 60 mm can be manufactured as per outer diameter/ inner diameter, inner diameter/wall thickness or outer diameter/wall thickness measured. Tolerances per criteria will be agreed upon an individual basis. The max. siding typically measures 8% of the wall thickness. 2/13 11

12 Forms of Product OSRAM OVISIL tubing and rods are being mechanically manufactured from a melt of high pure, fine quartz sand subjected to own developed processes and stand out due to high homogeneity. All undoped as well as TiO 2 doped quartz glass types can be delivered in acid processed quality (index S, e.g. OVISIL 454 S). Acid wash may improve the optical transparency on some tubing types. All OVISIL glasses can be sealed with tungsten wires and rods using the sealing glasses 439, 440 and 441 (see brochure: OSRAM Silicate glasses ). The cut surfaces of the OVISIL -tubing may partially show various shades, which come into existence through a vacuum heating process. The impact to transmission features nevertheless is very limited. The cross sections of OVISIL 405, 406, 407, 481 and 482 have a bluish, whereas OVISIL 421, 422, 424, 461, 462, 464, 471, 472 and 474 have a violet appearance. Tubing: Quality of edges: rough cut for tubing from mm, length tolerance ± 10 mm (furnace cut). Depending on the quality requirements three different cutting methods are available for cut parts (fine cut): 1) dry cut for outer diameter range from 2,8-10,0 mm and length > 50 mm. 2) laser cut for outer diameter range from 6,8-35,0 mm and length mm; glazing of edges. 3) wet cut for outer diameter range from 2,8-44,0 mm and length mm. Length tolerances available upon request. Glazing of edges: Glazing of edges on cutparts is available upon request. Rod: We are manufacturing rods from OVISIL 451, 452, 454, 455 and 456 with these dimensions: Diameter tolerance Length Remarks range mm mm 1,5-30,0 ± 0, ± 10 furnace cut 2,3-30,0 ± 0,30 9,8-36,5 ± 1,0 cut parts Other sizes and tolerances can be manufactured upon request. 2/13 12

13 OVISIL 401, 402 The glasses OVISIL 401 and 402 are quartz glasses doped with cerium and other colorless metal oxides free of alkali. They show a greatly reduced UV-transmission and have approx. 50 K lower processing- and working-temperatures as compared to pure quartz glasses. All other mechanical and electrical properties are similar to the un-doped glasses. In particular, they can be sealed almost tension free with them. Thanks to the alkaline free doping the glasses show a high stability. They are suited for endurances up to approx. 950 C, if their surfaces are free of contaminations, especially alkaline containing impurities like finger sweat. Otherwise devitrification with consequent opaqueness and lower mechanical strength can be expected. Physical and Chemical Properties: Density [g/cm 3 ] 2,21 Transformation temperature [ C] 1165 Temperature [ C] 10 14,7 dpa s (strain point) 1128 at viscosity 10 13,2 dpa s (annealing point) ,6 dpa s (softening point) 1686 Maximum operational temperature, [ C] 950 continuously with periodical cooling Index of refraction at λ = 587,6 nm 1,459 These glasses contain dopants of approx. 0,9% CeO 2,Eu 2 O 3,TiO 2 and Al 2 O 3. Bakeable OH-content as per these guidance values: Typ 401 (unbaked) approx. 125 ppm OH Typ 402 (vacuum baked) 10 ppm OH 2/13 13

14 OVISIL 401, 402 Viscosity Transmittance of OVISIL 402 (wall thickness: 1 mm) Transmittance values to be observed: (wall thickness: 1 mm) Wave length λ [nm] Transmittance T [%] OVISIL 401 < 2,8 <3 >89 Transmittance T [%] OVISIL 402 < 2,8 <3 >89 2/13 14

15 OVISIL 405, 406, 407 The glasses OVISIL 405, 406, 407 are quartz glasses doped with cerium and other colorless metal oxides free of alkali. They show a greatly reduced UV-transmission and have approx. 100 K lower processing- and working-temperatures as compared to pure quartz glasses. All other mechanical and electrical properties are similar to the un-doped glasses. In particular, they can be sealed almost tension free with them. Thanks to the alkaline free doping the glasses show a high stability. They are suited for endurances up to approx. 900 C, if their surfaces are free of contaminations, especially alkaline containing impurities like finger sweat. Otherwise devitrification with consequent opaqueness and lower mechanical strength can be expected. Physical and Chemical Properties: Density [g/cm 3 ] 2,22 Transformation temperature [ C] 1100 Temperature [ C] 10 14,7 dpa s (strain point) 1045 at viscosity 10 13,2 dpa s (annealing point) ,6 dpa s (softening point) 1585 Maximum operational temperature, [ C] 900 continuously with periodical cooling Index of refraction at λ = 587,6 nm 1,459 These glasses contain dopants of approx. 1,8% Ce 2 O 3,AI 2 O 3, BaO and B 2 O 3. Bakeable OH-content as per these guidance values: Typ 405 (unbaked) approx. 70 ppm OH Typ 406 (vacuum baked) 4 ppm OH Typ 407 (after treated) 20 ppm OH 2/13 15

16 OVISIL 405, 406, 407 Viscosity Transmittance of OVISIL 406 (wall thickness: 1 mm) Transmittance values to be observed: (wall thickness: 1 mm) Wave length λ [nm] Transmittance T [%] OVISIL 405 < 17 < 15 > 90 Transmittance T [%] OVISIL 406 < 17 < 22 > 89 Transmittance T [%] OVISIL 407 < 1,8 < 0,25 > 89 2/13 16

17 OVISIL 421, 422, 424 These OVISIL quartz glasses consist up to 99,9% of silicon dioxide. They are particular high viscous and high melting. Because of their high transition- and softening-temperatures as well as their thermal stress resistance they are suitable for the manufacture of highly loaded light sources. OVISIL 421, 422 and 424 contain TiO 2 for the control of the transmittance in UV-C. They are suited for endurances up to approx C, if their surfaces are free of contaminations, especially alkaline containing impurities like hand perspiration. Otherwise devitrification with consequent opaqueness and lower mechnical strength can be expected. In comparison to OVISIL 461, 462 and 464 these quartz glasses have an improved transmission above 310 nm. Physical and Chemical Properties: Coefficient of expansion C [10-6 /K] 0,54 Young s modulus [GPa] 66 Poisson s ratio 0,17 Density [g/cm 3 ] 2,21 Thermal stress resistance for 8 N/mm 2 [K] 370 Transformation temperature [ C] 1200 Temperature [ C] 10 14,7 dpa s (strain point) 1167 at viscosity 10 13,2 dpa s (annealing point) ,6 dpa s (softening point) 1760 Maximum operational temperature, [ C] 1000 continuously with periodical cooling Birefrigence factor at 540 nm [10-6 mm 2 /N] 3,54 Index of refraction at λ = 587,6 nm 1,459 Chemical Composition: OVISIL quartz glasses 421, 422, 424 contains doping of 0,013% TiO 2. Bakeable OH-content as per these guidance values: Typ 421 (unbaked) approx. 150 ppm OH Typ 422 (vacuum baked) 4 ppm OH Typ 424 (vacuum baked) 1 ppm OH No change of these data by acid processing (index S ). 2/13 17

18 OVISIL 421, 422, 424 Viscosity Transmittance (wall thickness: 1 mm) Transmittance values to be observed: (wall thickness: 1 mm) Wave length λ [nm] Transmittance T [%] OVISIL 421 >10 >50 >76 <21 <65 <84 >87 >91 Transmittance T [%] OVISIL 422 < 65 > 90 > 90,8 Transmittance T [%] OVISIL 424 < 65 > 90 > 90,8 2/13 18

19 OVISIL 451, 452, 454 These OVISIL quartz glasses consist up to 99,99% of silicon dioxide and are free of dopings. They are particular high viscous and high melting. Because of their high transition- and softeningtemperatures as well as their thermal stress resistance they are suitable for the manufacture of highly loaded light sources. They are suited for endurances up to approx C, if their surfaces are free of contaminations, especially alkaline containing impurities like finger sweat. Otherwise devitrification with consequent opaqueness and lower mechanical strength can be expected. Physical and Chemical Properties: Coefficient of expansion C [10-6 /K] 0,54 Young s modulus [GPa] 66 Poisson s ratio 0,17 Density [g/cm 3 ] 2,21 Thermal stress resistance for 8 N/mm 2 [K] 370 Transformation temperature [ C] 1200 Temperature [ C] 10 14,7 dpa s (strain point) 1167 at viscosity 10 13,2 dpa s (annealing point) ,6 dpa s (softening point) 1760 Maximum operational temperature, [ C] 1000 continuously with periodical cooling Temperature [ C] at Ω cm 240 electrical resistivity 10 8 Ω cm ( t K100 ) Ω cm 1660 Resistivity at 250 C [Ω cm] at 350 C [Ω cm] Dielectric constant at 10 6 Hz and 20 C 3,7 Dielectric loss factor at 10 6 Hz and 20 C [10-3 ] 0,1 Birefrigence factor at 540 nm [10-6 mm 2 /N] 3,54 Index of refraction at λ = 587,6 nm 1,459 Chemical Composition: Please see page 10. Bakeable OH-content as per these guidance values: Typ 451 (unbaked) 120 ppm OH Typ 452 (vacuum baked) 4 ppm OH Typ 454 (vacuum baked) < 1 ppm OH No change of these data by acid processing (index S ). 2/13 19

20 OVISIL 451, 452, 454 Viscosity Transmittance (wall thickness: 1 mm) Transmittance values to be observed: (wall thickness: 1 mm) Wave length λ [nm] Transmittance T [%] OVISIL 451 > 85 > 90 >91 >92 Transmittance T [%] OVISIL 452 > 84 > 90 Transmittance T [%] OVISIL 454 > 84 > 90 2/13 20

21 OVISIL 451, 452, 454 Spectral transmittance IR-area of unbaked and vacuum baked tubing at 1mm wall thickness OVISIL 451 OVISIL OH-content: OVISIL 451 OVISIL 452 OVISIL 454 approx. 150 ppm 4 ppm < 1 ppm 2/13 21

22 OVISIL 455, 456 OVISIL 455 and 456 are quartz glasses doped with colourless metal oxides, having a lower processing temperature by 200 K and max working temperature by 150 K compared to undoped tubing. Any other mechanical and electrical features are very similar to undoped quartz tubing. In particular, they can be sealed almost tension free with them. The processing of OVISIL 455 and 456 and its usage in lamps might violate patents of third parties in some countries. OSRAM cannot furnish a guarantee caused by processing and usage in lamps of this type of quartz glass which might violate different trade mark rights. The buyer bears the full risk of this possible intervention. Physical and Chemical Properties: Coefficient of expansion C [10-6 /K] 0,54 Young s modulus [GPa] 66 Poisson s ratio 0,17 Density [g/cm 3 ] 2,21 Thermal stress resistance for 8 N/mm 2 [K] 370 Transformation temperature [ C] 1050 Temperature [ C] 10 14,7 dpa s (strain point) 992 at viscosity 10 13,2 dpa s (annealing point) ,6 dpa s (softening point) 1545 Maximum operational temperature, [ C] 850 continuously with periodical cooling Birefrigence factor at 540 nm [10-6 mm 2 /N] 3,54 Index of refraction at λ = 587,6 nm 1,459 These glasses contain dopants of approx. 500 ppm, K 2 O, AI 2 O 3 and earth alkaline oxides. Bakeable OH-content as per these guidance values: Typ 455 (unbaked) approx. 75 ppm OH Typ 456 (vacuum baked) < 4 ppm OH 2/13 22

23 OVISIL 455, 456 Viscosity Transmittance (wall thickness: 1 mm) Transmission [%] Wave Length [nm] Spectral transmittance IR-area of unbaked and vacuum baked tubing at 1mm wall thickness OVISIL 455 OVISIL /13 23

24 OVISIL 461, 462, 464 These OVISIL quartz glasses consist up to 99,9% of silicon dioxide. They are particular high viscous and high melting. Because of their high transition- and softening-temperatures as well as their thermal stress resistance they are suitable for the manufacture of highly loaded light sources. OVISIL 461, 462 and 464 contain TiO 2 for the control of the transmittance in UV-C. They are suited for endurances up to approx C, if their surfaces are free of contaminations, especially alkaline containing impurities like finger sweat. Otherwise devitrification with consequent opaqueness and lower mechanical strength can be expected. Physical and Chemical Properties: Coefficient of expansion C [10-6 /K] 0,54 Young s modulus [GPa] 66 Poisson s ratio 0,17 Density [g/cm 3 ] 2,21 Thermal stress resistance for 8 N/mm 2 [K] 370 Transformation temperature [ C] 1200 Temperature [ C] 10 14,7 dpa s (strain point) 1167 at viscosity 10 13,2 dpa s (annealing point) ,6 dpa s (softening point) 1760 Maximum operational temperature, [ C] 1000 continuously with periodical cooling Birefrigence factor at 540 nm [10-6 mm 2 /N] 3,54 Index of refraction at λ = 587,6 nm 1,459 Chemical Composition: OVISIL quartz glasses 461, 462, 464 contains doping of 0,02% TiO 2. Bakeable OH-content as per these guidance values: Typ 461 (unbaked) approx. 150 ppm OH Typ 462 (vacuum baked) 4 ppm OH Typ 464 (vacuum baked) 1 ppm OH No change of these data by acid processing (index S ). 2/13 24

25 OVISIL 461, 462, 464 Viscosity Transmittance (wall thickness: 1 mm) Transmittance values to be observed: (wall thickness: 1 mm) Wave length λ [nm] Transmittance T [%] OVISIL 461 > 3,5 > 35 > 72 <11 <50 <79 >85 Transmittance T [%] OVISIL 462 < 52 > 89 Transmittance T [%] OVISIL 464 < 52 > 88 2/13 25

26 OVISIL 471, 472, 474 These OVISIL quartz glasses consist up to 99,8% of silicon dioxide. They contain TiO 2 for the control of the transmittance in UV-C. They are particular high viscous and high melting. Because of their high transition- and softening-temperatures as well as their thermal stress resistance they are suitable for the manufacture of highly loaded light sources. They are suited for endurances up to approx C, if their surfaces are free of contaminations, especially alkaline containing impurities like finger sweat. Otherwise devitrification with consequent opaqueness and lower mechanical strength can be expected. Physical and Chemical Properties: Coefficient of expansion C [10-6 /K] 0,54 Young s modulus [GPa] 66 Poisson s ratio 0,17 Density [g/cm 3 ] 2,21 Thermal stress resistance for 8 N/mm 2 [K] 370 Transformation temperature [ C] 1200 Temperature [ C] 10 14,7 dpa s (strain point) 1167 at viscosity 10 13,2 dpa s (annealing point) ,6 dpa s (softening point) 1760 Maximum operational temperature, [ C] 1000 continuously with periodical cooling Birefrigence factor at 540 nm [10-6 mm 2 /N] 3,54 Index of refraction at λ = 587,6 nm 1,459 Chemical Composition: OVISIL quartz glasses 471, 472, 474 contains doping of 0,125% TiO 2. Bakeable OH-content as per these guidance values: Typ 471 (unbaked) approx. 150 ppm OH Typ 472 (vacuum baked) 4 ppm OH Typ 474 (vacuum baked) 1 ppm OH No change of these data by acid processing (index S ). 2/13 26

27 OVISIL 471, 472, 474 Viscosity Transmittance (wall thickness: 1 mm) Transmission [%] Transmittance values to be observed: (wall thickness: 1 mm) Wave length λ [nm] Transmittance T [%] OVISIL 471 < 4 < 5 < 38 > 74 Transmittance T [%] OVISIL 472 < 46 > 89 Transmittance T [%] OVISIL 474 < 46 > 88 2/13 27

28 OVISIL 481, 482 The glasses OVISIL 481 and 482 are quartz glasses doped with cerium oxide. They show a greatly reduced UV-transmission and have approx. 50 K lower processing- and working-temperatures as compared to pure quartz glasses. All other mechanical and electrical properties are similar to the undoped glasses. In particular, they can be sealed almost tension free with them. The glasses show a high stability, they are suited for endurances up to approx. 950 C, if their surfaces are free of contaminations, especially alkaline containing impurities like finger sweat. Otherwise devitrification with consequent opaqueness and lower mechanical strength can be expected. Physical and Chemical Properties: Coefficient of expansion C [10-6 /K] 0,54 Young s modulus [GPa] 66 Poisson s ratio 0,17 Density [g/cm 3 ] 2,21 Thermal stress resistance for 8 N/mm 2 [K] 370 Transformation temperature [ C] 1170 Temperature [ C] 10 14,7 dpa s (strain point) 1130 at viscosity 10 13,2 dpa s (annealing point) ,6 dpa s (softening point) 1715 Maximum operational temperature, [ C] 950 continuously with periodical cooling Index of refraction at λ = 587,6 nm 1,459 OVISIL quartz glasses 481, 482 contains doping of approx ppm, Ce 2 O 3,AI 2 O 3 and TiO 2. Bakeable OH-content as per these guidance values: Typ 481 (unbaked) approx. 100 ppm OH Typ 482 (vacuum baked) 4 ppm OH 2/13 28

29 OVISIL 481, 482 Viscosity Transmittance (wall thickness: 1 mm) Transmittance values to be observed: (wall thickness: 1 mm) Wave length λ [nm] Transmittance T [%] OVISIL 481 < 28 < 45 > 90 Transmittance T [%] OVISIL 482 < 27 < 50 > 89 2/13 29