Boron Carbide vs. Alumina
Boron carbide belongs to the non-oxide engineering ceramics classification, while alumina belongs to the oxide-based engineering ceramics. There are 20 material properties with values for both materials. Properties with values for just one material (6, in this case) are not shown.
For each property being compared, the top bar is boron carbide and the bottom bar is alumina.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 1710 to 2200 | |
| 1920 to 2750 |
| Elastic (Young's, Tensile) Modulus, GPa | 240 to 460 | |
| 220 to 370 |
| Flexural Strength, MPa | 170 to 410 | |
| 260 to 430 |
| Fracture Toughness, MPa-m1/2 | 2.5 to 3.5 | |
| 3.7 to 7.2 |
| Knoop Hardness | 2600 to 3200 | |
| 960 to 1660 |
| Poisson's Ratio | 0.17 to 0.19 | |
| 0.22 to 0.24 |
| Tensile Strength: Ultimate (UTS), MPa | 350 | |
| 210 to 290 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 1000 to 2500 | |
| 650 to 1730 |
| Specific Heat Capacity, J/kg-K | 950 | |
| 870 to 940 |
| Thermal Conductivity, W/m-K | 31 to 90 | |
| 14 to 30 |
| Thermal Expansion, µm/m-K | 4.5 to 5.6 | |
| 6.7 to 8.2 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 6.4 | |
| 7.8 to 11 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 0 to 11 | |
| 6.2 to 14 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.1 to 2.7 | |
| 3.4 to 4.1 |
Common Calculations
| Stiffness to Weight: Axial, points | 63 to 100 | |
| 35 to 53 |
| Stiffness to Weight: Bending, points | 91 to 100 | |
| 57 to 62 |
| Strength to Weight: Axial, points | 37 to 47 | |
| 14 to 23 |
| Strength to Weight: Bending, points | 42 to 53 | |
| 19 to 28 |
| Thermal Diffusivity, mm2/s | 16 to 38 | |
| 3.7 to 10 |
| Thermal Shock Resistance, points | 9.7 to 20 | |
| 4.9 to 14 |