Astrosital, Astrosital Properties

Astrosital (Russian equivalent to Zerodur) is a glass-ceramic material with ultra low thermal expansion. It is widely used as substrate material for astronomic mirrors.
Maximum available size: 500 mm Dia.

Coefficient of linear thermal expansion, 1/K from 213K to 333K from 293K to 573K	0.0 (+/-0.6) x 10^-7 2.8 (+/-1.0) x 10^-7
Density, g/cm³ at 293 K	2.46
Young's Modulus, GPa	90.2
Poisson's Ratio	0.28
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, n_d	1.536 +/- 0.004
Mean Dispersion, n_f-n_c	0.0102 +/- 0.0003