ASTROSITAL
Many optical applications require a substrate material with a near-zero coefficient of
thermal expansion and/or excellent thermal shock resistance. Astrosital, equivalent to
Zerodur™ (registered trademark of Schott Glass Technologies) is
a glass-ceramic material with ultra low thermal expansion.
Astronomical and x-ray telescope mirrors are prime examples of application. Another well
known application is production of mirror substrates for microlithography.
Maximum available size: 2,000 mm Dia (or 1,000 mm Square) x 300 mm thick.
Main Properties
| Astrosital | Zerodur | |
| Coefficient of linear thermal expansion, 1/K from 213K to 333K from 293K to 573K |
|
0.5 (+/-1) x 10-7 |
| Density, g/cm3 at 293 K | 2.46 |
2.53 |
| Young's Modulus, GPa | 90.2 |
91 |
| Poisson's Ratio | 0.28 |
0.24 |
| Bending Strength, GPa | 166 |
|
| Relative to BK-7 abrasion hardness | 1.78 |
|
| Specific Heat, kJ/(kg K) | 0.92 |
|
| Thermal Conductivity, W/(m K) | 1.71 |
|
| Heat Resistance, K | 823 | |
| Refractive Index, nd | 1.536 +/- 0.004 | |
| Mean Dispersion, nf - nc | 0.0102 +/- 0.0003 |
Standard Telescope Mirrors:
2"-diam w. 1/20th Wave Astrosital-Zero Expansion Mirror $149
5"-diam w. 1/20th Wave Astrosital-Zero Expansion Mirror $499
| Del Mar Ventures 12595 Ruette Alliante #148 San Diego, CA 92130 v/fax: (509) 752-0123 optics@sciner.com http://www.sciner.com/Opticsland/ |
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