Silicon Carbide vs. Alumina
Silicon 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 silicon carbide and the bottom bar is alumina.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 2780 to 3900 | |
| 1920 to 2750 |
| Elastic (Young's, Tensile) Modulus, GPa | 370 to 490 | |
| 220 to 370 |
| Flexural Strength, MPa | 410 to 600 | |
| 260 to 430 |
| Fracture Toughness, MPa-m1/2 | 3.4 to 4.6 | |
| 3.7 to 7.2 |
| Knoop Hardness | 2500 to 2900 | |
| 960 to 1660 |
| Poisson's Ratio | 0.14 to 0.21 | |
| 0.22 to 0.24 |
| Tensile Strength: Ultimate (UTS), MPa | 210 to 370 | |
| 210 to 290 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 500 to 1590 | |
| 650 to 1730 |
| Maximum Thermal Shock, °C | 210 to 660 | |
| 200 to 300 |
| Specific Heat Capacity, J/kg-K | 670 to 1180 | |
| 870 to 940 |
| Thermal Conductivity, W/m-K | 120 to 170 | |
| 14 to 30 |
| Thermal Expansion, µm/m-K | 4.0 to 4.5 | |
| 6.7 to 8.2 |
Electrical Properties
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 0.94 to 3.3 | |
| 6.2 to 14 |
Otherwise Unclassified Properties
| Density, g/cm3 | 3.0 to 3.2 | |
| 3.4 to 4.1 |
Common Calculations
| Stiffness to Weight: Axial, points | 69 to 84 | |
| 35 to 53 |
| Stiffness to Weight: Bending, points | 79 to 82 | |
| 57 to 62 |
| Strength to Weight: Axial, points | 18 to 34 | |
| 14 to 23 |
| Strength to Weight: Bending, points | 24 to 38 | |
| 19 to 28 |
| Thermal Diffusivity, mm2/s | 38 to 79 | |
| 3.7 to 10 |
| Thermal Shock Resistance, points | 6.9 to 18 | |
| 4.9 to 14 |