Sapphire, ruby synthetic monocrystalline
Exception of diamonds, industrial sapphire is a material harder than any other natural material, with hardness 9 on the Mohs scale. Ruby is a kind of corundum in red color, main component is aluminum oxide (Al2O3). The red color from chromium (Cr), mainly Cr2O3 about 0.1~3%, and the highest at 4%. The chemical and mechanical properties of synthetic ruby is same as sapphire, ruby main used for bearing, compass, meters etc.
| Sapphire characteristic parameters | |
| MECHANICAL PROPERTIES | |
| Young Modulus : | 345 GPa |
| Shear Modulus: | 145 GPa |
| Bulk Modulus: | 240 GPa |
| Knoop Hardness: | 22 GPa |
| Mohs Hardness: | 9 |
| Vickers Hardness: | 1570-1750 |
| Modulus of Rupture: | 420 MPa at 20°C 280 Mpa at 500°C |
| Apparent Elastic Limit: | 275 MPa |
| Poisson constant: | 0.30 |
| Density: | 3.98 g/cm3 at 20°C |
| THERMAL PROPERTIES | |
| Melting Point: | 2030°C |
| Specific Heat: | 105 J/kg.°C at – 182.15°C 761 J/kg.°C at 17.85°C |
| Coefficient of thermal expansion: | 6.66 x 10-6 K-1 // c axis at 50°C 5 x 10-6 K-1 ┴ c axis at 50°C |
| Thermal conductivity: | 10000 (W/m·°C) at -243°C 40 (W/m·°C ) at 27°C 4 (W/m·°C ) at 1227°C |
| ELECTRICAL PROPERTIES | |
| Resisitivity: | 1016 Ω-cm at 27°C 1011 Ω-cm at 300°C |
| Dielectric resistance at 60Hz: | 48x106 V/m |
| Dielectric Strength: | 17kV/mm |
| Dielectric Costant: | 10.6 // c axis at 27°C ; 106Hz 8.6 ┴ c axis at 27°C ; 106Hz |
| Loss coefficient: | < 103 at 27°C |
| OPTICAL PROPERTIES | |
| Transmittance: | Excellent in the visible >60% da 0,25μm - 0,4μm >85% da 0.75μm - 5μm (thickness: 1mm) |
| Refractive Index: | n0 = 1.7717; ne = 1.76355 at 50.532μm |
| Puissance dispersivity (nf-nc): | 0.011; λf = 0.4861μm; λc = 0.6563μm |
| Emissivity: | < 0.02 @ 880°C; λ = 2.6 at 3.7μm |
| dn/dt: | 13 x 10-6K-1 |
| Note: The above data only for reference, specific details please refer to actual test data. | |
Transmission Curve:
