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Sapphire Data

About Sapphire

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 Properties
Optical transmission range, µm0.18 – 5.5
Refractive index at 0.532 µmno = 1.7717, ne = 1.76355
Mechanical Properties
Density g/cm33,97–3.99
 Mohs Mohs
 Knoop kg/mm2||C 1525–1800 | C 1900–2100
 Vickers (9.8N) GPa||C 16-17 | C 18-20
Young’s modulus GPa345–494
Tensile strength MPa400at 298K275at 770K335at 1000K
Compressive strength (Bulk modulus) GPa2–2.9
Flexural strength GPa||C 1.03 | C 1.54
compression modulus GPa250
Rigidity modulus GPa145–175
Repture modulus (MOR) MPa350–690
Elasticity modulus N/mm23.6x105
Poisson’s ratio0.27–0.30
Jet abrasion resistance (acc. to Mackensen)0.12 mm
Friction Coefficient0.15 on Steel, 0.10 on Sapphire
Thermal Properties
Melting point2323 K (2050 °C)
Boiling point3253 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/mK30 K10000 298 K||C 32.5 | C 30.3670 K12.56 1500 K4.0 
Electrical Properties
Resistivity Ωcm293 K||C(1.2–2.9)x1019  | C5x1018573 K 10111270 K 1091770 K 1052270 K 103
Dielectric constant293 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 loss293 K, 1010 Hz   ||C 8.610–5   | C 3.010–5
Dielectric strength V/m48x106


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