The combination from high E-modul, extreme hardness, brilliant optical characteristics and mechanical and chemical resistance offers phenomenal advantages compared against glass or ceramic!
Sapphire windows have good ansmissivity and high permeation ratio when the wavelength is from 0,2µm; to 5,5 µmBasic properties | |
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Crystalline structure | Hexagonal a=b=4.77Å c=13.04 Å |
Melting Point | 2040 °C |
Thermal expansion index | 6,7x10 -6 parallel to C-axis |
Conductivity | 46.06 W/m °K at 0°C |
Specific resistivity | 5,0 x 10 -6 C perpendicular to C-axis |
Dielectric Constant | average 11.5 (parallel to C-axis) |
Density | 3.98g/cm³ |
Compressive Strength | 2 GPa |
Young's Modulus | 3.6 x 10 4 - 4.4 x 10 4 |
Flexural Strength | 35-39 daN/mm2 |
Tensile Strength | ~400 MPa (at approx. 25°C) |
Poisson's Ratio | 0.28-0.33 |
Hardness | 9 mohs 1800 Knoo parallel to c-axis 2200 Knoop perpendicular to c-axis |
Refraction Index | No: 1.768 (c-axis) NE: 1.760 (c-axis) |
Birefringence | (No-Ne) 0.008 |