Technical Details of AS 87 neo
Mechanical properties | |
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Density p (annealed at 40 °C/h) |
2.46 g/cm3 |
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Chemical strengthening | thickness in mm temperature J in °C time t in min compressive stress (CS) in MPa depth of layer (DoL) in μm |
0.075 > 10 |
0.33 > 12 |
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Young‘s modulus E | 71.9 kN/mm2 | ||||||
Poisson‘s ratio μ | 0.216 | ||||||
Torsion modulus G | 29.6 kN/mm2 | ||||||
Knoop hardness HK 0.1/20 | 490 | ||||||
Vickers hardness HV 0.2/25 | 560 |
Thermal properties | |||||||
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Coefficient of thermal expansion (CTE) α (20-300 °C) |
9.2 · 10-6 K-1 |
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Mean specific heat capacity c p(20 –100 °C) |
0.87 J/(g · K) |
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Transformation temperature Tg | 598 °C | ||||||
Viscosities | Viscosity in η in dPas |
Temperature in °C |
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Strain point | 14.5 | 577 | |||||
Annealing point | 13.0 | 616 | |||||
Softening point | 7.6 | 855 |
Optical properties | |||||||
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Refractive indices | ng | 1.5151 | |||||
Pretreatment of samples | nF' | 1.5109 | |||||
Condition as supplied | nF | 1.5104 | |||||
[„as drawn“] | ne | 1.5065 | |||||
nd | 1.5044 | ||||||
nD | 1.5043 ± 0.0015 | ||||||
nC' | 1.5022 | ||||||
nC | 1.5017 | ||||||
Abbe value | ve | 57.7 | |||||
Photoelastic constant C [nm/(cm*MPa)] |
29.0 |
Transmittance values | |||||||
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Thickness 0.33 mm | wavelength at 254 nm at 380 nm at 632.8 nm at 1064 nm |
τ (λ) in % 31.1 91.6 92.2 92.4 |
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Edge wavelength λC ( τ = 0.46) |
thickness in mm 0.075 0.33 |
wavelength in nm 230 266 |
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Luminous transmittance τvD65 in % |
0.33 | 92 |
Chemical properties | ||||||||
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Hydrolytic resistance acc. to DIN ISO 719 | ||||||||
Class | HGB 2 |
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Equivalent of alkali per gram of glass grains [µg/g] | 56 | |||||||
Acid resistance acc. to DIN 12 116 | ||||||||
Class | S 4 | |||||||
Half surface weight loss after 6 hours [mg/dm²] | 61 | |||||||
Alkali resistance acc. to ISO 695 | ||||||||
Class | A 1 | |||||||
Surface weight loss after 3 hours [mg/dm²] | 66 |
Electrical properties | |||||||
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Dielectric constant ɛr (at ν = 25°C) |
at 1 MHz at 1 GHz at 5 GHz |
8.4 7.6 7.5 |
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Dissipation factor tan δ (at ν = 25°C) |
at 1 MHz at 1 GHz at 5 GHz |
252 · 10-4 176 · 10-4 217 · 10-4 |
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Conductivity (at ν = 25°C) |
in S/cm direct current |
160 · 10-12 |