Fused Silica vs. Potassium Bromide
Fused silica belongs to the glass and glass-ceramics classification, while potassium bromide belongs to the non-glass optical ceramics. There are 15 material properties with values for both materials. Properties with values for just one material (11, in this case) are not shown.
For each property being compared, the top bar is fused silica and the bottom bar is potassium bromide.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 73 | |
| 24 |
| Poisson's Ratio | 0.17 | |
| 0.17 |
| Shear Modulus, GPa | 31 | |
| 7.0 |
Thermal Properties
| Melting Onset (Solidus), °C | 1900 | |
| 730 |
| Specific Heat Capacity, J/kg-K | 720 | |
| 450 |
| Thermal Conductivity, W/m-K | 1.4 | |
| 4.8 |
| Thermal Expansion, µm/m-K | 0.5 | |
| 39 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 3.8 | |
| 4.9 |
| Electrical Dissipation At 1 MHz | 0.00011 | |
| 0.00020 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.2 | |
| 2.8 |
| Light Transmission Range, µm | 0.16 to 3.5 | |
| 0.22 to 26 |
| Refractive Index | 1.5 | |
| 1.8 |
Common Calculations
| Stiffness to Weight: Axial, points | 18 | |
| 4.7 |
| Stiffness to Weight: Bending, points | 63 | |
| 35 |
| Thermal Diffusivity, mm2/s | 0.85 | |
| 3.9 |