Synthetic Sapphire vs. Hexagonal Boron Nitride
Synthetic sapphire belongs to the oxide-based engineering ceramics classification, while hexagonal boron nitride belongs to the non-oxide engineering ceramics. There are 15 material properties with values for both materials. Properties with values for just one material (13, 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 hexagonal boron nitride.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 2700 | |
| 21 to 250 |
| Elastic (Young's, Tensile) Modulus, GPa | 450 | |
| 14 to 60 |
| Flexural Strength, MPa | 1090 | |
| 18 to 140 |
| Poisson's Ratio | 0.28 | |
| 0.11 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 2000 | |
| 1030 to 2350 |
| Specific Heat Capacity, J/kg-K | 760 | |
| 840 to 1610 |
| Thermal Conductivity, W/m-K | 30 | |
| 29 to 96 |
| Thermal Expansion, µm/m-K | 5.3 | |
| 0.54 to 18 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 10 | |
| 4.0 to 4.4 |
| Dielectric Strength (Breakdown Potential), kV/mm | 9.9 | |
| 61 to 200 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 17 | |
| 13 to 15 |
Otherwise Unclassified Properties
| Density, g/cm3 | 4.0 | |
| 1.9 to 2.1 |
Common Calculations
| Stiffness to Weight: Axial, points | 63 | |
| 4.1 to 18 |
| Stiffness to Weight: Bending, points | 64 | |
| 42 to 69 |
| Thermal Diffusivity, mm2/s | 9.9 | |
| 9.9 to 34 |