Optical Silicon vs. Zirconia
Optical silicon belongs to the non-glass optical ceramics classification, while zirconia belongs to the oxide-based engineering ceramics. There are 19 material properties with values for both materials. Properties with values for just one material (7, in this case) are not shown. Please note that the two materials have significantly dissimilar densities. This means that additional care is required when interpreting the data, because some material properties are based on units of mass, while others are based on units of area or volume.
For each property being compared, the top bar is optical silicon and the bottom bar is zirconia.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 120 | |
| 1260 to 3080 |
| Elastic (Young's, Tensile) Modulus, GPa | 150 | |
| 190 to 200 |
| Flexural Strength, MPa | 300 | |
| 630 to 970 |
| Fracture Toughness, MPa-m1/2 | 3.5 | |
| 8.0 to 11 |
| Knoop Hardness | 1130 | |
| 1210 to 1300 |
| Poisson's Ratio | 0.28 | |
| 0.25 to 0.29 |
| Tensile Strength: Ultimate (UTS), MPa | 110 | |
| 410 to 450 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 1350 | |
| 500 to 1330 |
| Specific Heat Capacity, J/kg-K | 700 | |
| 400 to 510 |
| Thermal Conductivity, W/m-K | 150 | |
| 2.2 to 4.3 |
| Thermal Expansion, µm/m-K | 3.0 | |
| 8.8 to 9.5 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 12 | |
| 28 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.3 | |
| 5.7 to 6.0 |
Common Calculations
| Stiffness to Weight: Axial, points | 35 | |
| 19 |
| Stiffness to Weight: Bending, points | 75 | |
| 33 to 34 |
| Strength to Weight: Axial, points | 13 | |
| 19 to 22 |
| Strength to Weight: Bending, points | 22 | |
| 21 to 23 |
| Thermal Diffusivity, mm2/s | 93 | |
| 0.73 to 1.8 |
| Thermal Shock Resistance, points | 18 | |
| 15 to 19 |