Synthetic Sapphire vs. Hafnia
Both synthetic sapphire and hafnia are oxide-based engineering ceramics. There are 11 material properties with values for both materials. Properties with values for just one material (14, 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 synthetic sapphire and the bottom bar is hafnia.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 450 | |
| 57 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 2000 | |
| 2800 |
| Melting Onset (Solidus), °C | 2050 | |
| 2900 |
| Specific Heat Capacity, J/kg-K | 760 | |
| 120 |
| Thermal Conductivity, W/m-K | 30 | |
| 1.1 |
| Thermal Expansion, µm/m-K | 5.3 | |
| 6.0 |
Electrical Properties
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 17 | |
| 9.0 |
Otherwise Unclassified Properties
| Density, g/cm3 | 4.0 | |
| 9.7 |
Common Calculations
| Stiffness to Weight: Axial, points | 63 | |
| 3.3 |
| Stiffness to Weight: Bending, points | 64 | |
| 13 |
| Thermal Diffusivity, mm2/s | 9.9 | |
| 0.95 |