Synthetic sapphire is a single crystal form of corundum, Aluminum Oxide (Al2O3). Sapphire is aluminum oxide in its purest form with no porosity or grain boundaries, making it theoretically dense. Sapphire’s exceptional optical, physical, thermal, mechanical, electrical and chemical properties along with its superior radiation stability making sapphire material a favorable and preferred material choice for scientific studies and many applications (including military, medical, semiconductor, optical industries etc. ) which demanding high performances.
Some Outstanding Properties of Sapphire To Be Mentioned:
• Second only to diamond in hardness. This makes sapphire material extremely scratch resistant. Coupled with its excellent optical characteristics, sapphire is the ideal material for mobile phone panels, scanner windows and watches etc. Sapphire is also commonly used in some non-optical applications such as bearings and nozzles.
• Excellent transmission in a wide range from UV to IR
• Extremely good thermal conductivity and thermal stability at very high temperatures (>1600C) makes sapphire an ideal material for semiconductor processing, furnace applications and refining applications etc.
• Chemical inertness and outstanding durability against aggressive media makes sapphire an ideal material for chemical processing, plasma systems and semiconductor processing.
• High electric resistance, high dielectric constant and low loss tangent makes sapphire an ideal material for semiconductor, electrical and microwave applications.
|
| Optical transmission range, µm | 0.18 – 5.5 |
| Refractive index at 0.532 µm | no = 1.7717, ne = 1.76355 |
|
| Density g/cm3 | 3,97–3.99 |
Hardness
Mohs Mohs |
9 |
| Knoop kg/mm2 | ||C 1525–1800 | C 1900–2100 |
| Vickers (9.8N) GPa | ||C 16-17 | C 18-20 |
| Young’s modulus GPa | 345–494 |
| Tensile strength MPa | 400at 298K275at 770K335at 1000K |
| Compressive strength (Bulk modulus) GPa | 2–2.9 |
| Flexural strength GPa | ||C 1.03 | C 1.54 |
| compression modulus GPa | 250 |
| Rigidity modulus GPa | 145–175 |
| Repture modulus (MOR) MPa | 350–690 |
| Elasticity modulus N/mm2 | 3.6x105 |
| Poisson’s ratio | 0.27–0.30 |
| Jet abrasion resistance (acc. to Mackensen) | 0.12 mm |
| Friction Coefficient | 0.15 on Steel, 0.10 on Sapphire |
|
| Melting point | 2323 K (2050 °C) |
| Boiling point | 3253 K (2980 °C) |
| Thermal expansion coefficient (x10–6K–1) | 293–323 K||C 6.6 | C 5.0310–670 K||C 7.0 | C 7.71270 K||C 9.03 | C 8.3160 degr. to C-axis:293-323K 5.8 1270K 8.4 1770K 9.0 |
| Thermal conductivity W/mK | 30 K10000 298 K||C 32.5 | C 30.3670 K12.56 1500 K4.0 |
|
| Resistivity Ωcm | 293 K||C(1.2–2.9)x1019 | C5x1018573 K 10111270 K 1091770 K 1052270 K 103 |
| Dielectric constant | 293 K (20 °C) | C 9.35||C 11.53370 K | C 9.43||C 11.66570 K | C 9.66||C 12.07770 K | C 9.92||C 12.54970 K | C 10.26||C 13.18293 K, 103–109 Hz | C 9.3||C 11.5 |
| Dielectric tangent loss | 293 K, 1010 Hz ||C 8.610–5 | C 3.010–5 |
| Dielectric strength V/m | 48x106 |
