Synthetic Sapphire vs. CVD Diamond
Synthetic sapphire belongs to the oxide-based engineering ceramics classification, while CVD diamond belongs to the non-oxide engineering ceramics. There are 18 material properties with values for both materials. Properties with values for just one material (8, in this case) are not shown.
For each property being compared, the top bar is synthetic sapphire and the bottom bar is CVD diamond.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 450 | |
| 1050 |
| Fracture Toughness, MPa-m1/2 | 1.9 | |
| 5.5 |
| Poisson's Ratio | 0.28 | |
| 0.1 |
| Tensile Strength: Ultimate (UTS), MPa | 2470 | |
| 750 |
Thermal Properties
| Specific Heat Capacity, J/kg-K | 760 | |
| 500 |
| Thermal Conductivity, W/m-K | 30 | |
| 1900 |
| Thermal Expansion, µm/m-K | 5.3 | |
| 1.0 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 10 | |
| 5.7 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 17 | |
| 13 |
Otherwise Unclassified Properties
| Density, g/cm3 | 4.0 | |
| 3.5 |
| Light Transmission Range, µm | 0.17 to 5.5 | |
| 0.22 to 100 |
| Refractive Index | 1.8 | |
| 2.4 |
Common Calculations
| Stiffness to Weight: Axial, points | 63 | |
| 170 |
| Stiffness to Weight: Bending, points | 64 | |
| 96 |
| Strength to Weight: Axial, points | 170 | |
| 59 |
| Strength to Weight: Bending, points | 100 | |
| 52 |
| Thermal Diffusivity, mm2/s | 9.9 | |
| 1080 |
| Thermal Shock Resistance, points | 74 | |
| 51 |