Alumina vs. Boron Carbide
Alumina belongs to the oxide-based engineering ceramics classification, while boron carbide belongs to the non-oxide 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 alumina and the bottom bar is boron carbide.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 1920 to 2750 | |
| 1710 to 2200 |
| Elastic (Young's, Tensile) Modulus, GPa | 220 to 370 | |
| 240 to 460 |
| Flexural Strength, MPa | 260 to 430 | |
| 170 to 410 |
| Fracture Toughness, MPa-m1/2 | 3.7 to 7.2 | |
| 2.5 to 3.5 |
| Knoop Hardness | 960 to 1660 | |
| 2600 to 3200 |
| Poisson's Ratio | 0.22 to 0.24 | |
| 0.17 to 0.19 |
| Tensile Strength: Ultimate (UTS), MPa | 210 to 290 | |
| 350 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 650 to 1730 | |
| 1000 to 2500 |
| Specific Heat Capacity, J/kg-K | 870 to 940 | |
| 950 |
| Thermal Conductivity, W/m-K | 14 to 30 | |
| 31 to 90 |
| Thermal Expansion, µm/m-K | 6.7 to 8.2 | |
| 4.5 to 5.6 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 7.8 to 11 | |
| 6.4 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 6.2 to 14 | |
| 0 to 11 |
Otherwise Unclassified Properties
| Density, g/cm3 | 3.4 to 4.1 | |
| 2.1 to 2.7 |
Common Calculations
| Stiffness to Weight: Axial, points | 35 to 53 | |
| 63 to 100 |
| Stiffness to Weight: Bending, points | 57 to 62 | |
| 91 to 100 |
| Strength to Weight: Axial, points | 14 to 23 | |
| 37 to 47 |
| Strength to Weight: Bending, points | 19 to 28 | |
| 42 to 53 |
| Thermal Diffusivity, mm2/s | 3.7 to 10 | |
| 16 to 38 |
| Thermal Shock Resistance, points | 4.9 to 14 | |
| 9.7 to 20 |