|
|
|
| Syntethic
Sapphire Properties |
properties of sapphire
| General Properties of Sapphire |
| |
Chemical
Formula |
AL203 |
| Optical |
| |
Index
of Refraction |
No:
1.768(c-axis) |
| |
|
Ne:
1.760(c-axis) |
| |
Birefringence |
(No-Ne)
0.008 |
| Mechanical |
| |
Density |
3.97
gm/cm3 |
| |
Compressive
Strength |
300,000
psi |
| |
Young
Modulus |
50-55
x 106 psi |
| |
Flexural
Strength |
~100,000
psi |
| |
Tensile
Strength |
~60,000
psi (at approx. 25°C) |
| |
Poisson’s
Ratio |
0.28-0.33 |
| |
Hardness |
9
mohs |
| |
|
1800
Knoop parallel to c-axis |
| |
|
2200
Knoop perpendicular to c-axis |
| |
Coefficient
of Friction |
0.15
against steel |
| |
Porosity |
0% |
| Electrical |
| |
Dielectric
Strength |
480,000
v/cm |
| |
Dielectric
Constant |
average
11.5 (parallel to c-axis) |
| |
|
average
9.3 (perpendicular to c-axis) |
| |
Volume
Resistivity |
>1014
ohm-cm2 |
| Thermal |
| |
Melting
Point |
2,050
°C |
| |
Coefficient
of Expansion |
5.3
x 10-6 (parallel to c-axis) |
| |
|
4.5
x 10-6 (perpendicular to c-axis) |
| |
Conductivity |
0.086
cal/gm |
| |
Heat
Capacity |
77.8
joules/deg. Mole |
|
|
|
