| Composition: |
99.996%Al2O3(Lewo
sapphire) |
| Crystal
structure£º |
Hexagonal-rhombohedral |
| Density: |
3.98g/cm3¡¡¡¡¡¡¡¡¡¡¡¡¡¡(20oc) |
| Melting
temperature: |
2050oC |
| Mohs
hardness£º |
9 |
| Knoop
hardness£º |
?C£º2200 |
| |
?C£º1800 |
| Flexural
strength: |
5000-7000kg/cm2 |
| Compressive
strength£º |
3.0GNm-2¡¡¡¡¡¡¡¡¡¡¡¡¡¡(25oc) |
| Young¡¯s
modulus£º |
4.2x10-2
GNm-2 |
| Coefficient
of liner thermal expansion: |
?C£º5.0x10-6 ¡¡¡¡¡¡¡¡¡¡¡¡¡¡(50oc) |
| |
?C£º6.6x10-6¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡(20oc-25oc) |
| No(Refraction
index @¦Ë=589.3nm): |
?C£º1.768 |
| |
?C£º1.760 |
| Optical
transmission(1mm thk.) |
0.15-6µm T>86% |
| Dielectric
constant at 1MHz£º |
?C£º9.3 (103-1010Hz, 25oC) |
| |
?C£º11.5 |
| Resistivity
at 200C
£º |
>1016¦¸.cm |
| Chemical
resistance£º |
Will
not be Eroded by acids or alkalis at normal temperature |
