Optical Silicon vs. Graphite
Optical silicon belongs to the non-glass optical ceramics classification, while graphite belongs to the non-oxide engineering ceramics. There are 13 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 optical silicon and the bottom bar is graphite.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 120 | |
| 90 |
| Elastic (Young's, Tensile) Modulus, GPa | 150 | |
| 21 |
| Flexural Strength, MPa | 300 | |
| 80 |
| Tensile Strength: Ultimate (UTS), MPa | 110 | |
| 18 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 1350 | |
| 220 |
| Thermal Conductivity, W/m-K | 150 | |
| 6.0 |
| Thermal Expansion, µm/m-K | 3.0 | |
| 4.9 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.3 | |
| 1.8 |
Common Calculations
| Stiffness to Weight: Axial, points | 35 | |
| 6.7 |
| Stiffness to Weight: Bending, points | 75 | |
| 53 |
| Strength to Weight: Axial, points | 13 | |
| 2.9 |
| Strength to Weight: Bending, points | 22 | |
| 8.7 |
| Thermal Shock Resistance, points | 18 | |
| 12 |