Synthetic Sapphire vs. Potassium Bromide
Synthetic sapphire belongs to the oxide-based engineering ceramics classification, while potassium bromide belongs to the non-glass optical ceramics. There are 14 material properties with values for both materials. Properties with values for just one material (12, in this case) are not shown.
For each property being compared, the top bar is synthetic sapphire and the bottom bar is potassium bromide.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 450 | |
| 24 |
| Poisson's Ratio | 0.28 | |
| 0.17 |
| Shear Modulus, GPa | 150 | |
| 7.0 |
Thermal Properties
| Melting Onset (Solidus), °C | 2050 | |
| 730 |
| Specific Heat Capacity, J/kg-K | 760 | |
| 450 |
| Thermal Conductivity, W/m-K | 30 | |
| 4.8 |
| Thermal Expansion, µm/m-K | 5.3 | |
| 39 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 10 | |
| 4.9 |
Otherwise Unclassified Properties
| Density, g/cm3 | 4.0 | |
| 2.8 |
| Light Transmission Range, µm | 0.17 to 5.5 | |
| 0.22 to 26 |
| Refractive Index | 1.8 | |
| 1.8 |
Common Calculations
| Stiffness to Weight: Axial, points | 63 | |
| 4.7 |
| Stiffness to Weight: Bending, points | 64 | |
| 35 |
| Thermal Diffusivity, mm2/s | 9.9 | |
| 3.9 |