Material | | Alumina Al2O3 | | | Zirconia ZrO2 | | Mixed oxides ZrO2/Al2O3 | | Silicon carbide SIC | | | Silicon nitride Si3N4 | | Boron nitride | Metal |
| | | | | | ATZ | ZTA | | | | | | | |
Brief description | | Al2O3 purity 96% | Al2O3 purity 99.7% | Mg-PSZ MgO partially stabilized | Y-TZP Y2O3 partially stabilized | ZrO2 particle-reinforced | Al2O3 particle-reinforced | SiSiC Si-infiltrated with 8-12% free Silicon | SSiC sintered without free silicon | HP SIC hot-pressed without free silicon | HP SN hot-pressed | SSN sintered | HP BN* hot-pressed | C-15* plain steel |
Color | | white | white | yellow | white | white | white | black | black | black | black | grey | white | - |
Structural properties | | | | | | | | | | | | | | |
Density | g/cm3 | 3.7 | 3.9 | 5.7 | >6.0 | 5.5 | 4.1 | 3.1 | 3.1 | 3.2 | 3.2 | 3.22 | 2 | 7.87 |
Open porosity | % | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Average crystal size | µm | 10 | 5 | 50 | 0.7 | 0.7 | 0.5 | 15 | 1 | 10 | 5 | 5 | - | - |
Mechanical properties | | | | | | | | | | | | | | |
Vickers hardness (HV10) | MPa | 1400 | 1800 | 1200 | 1300 | 1400 | 1700 | 2200 | 2500 | 2500 | 1600 | 1450 | 190 | 700 |
Compressive strength | MPa | 2800 | 2800 | 1600 | 2200 | 2100 | 2600 | 1200 | 2200 | 2900 | 2500 | 2500 | 160 | 1000 |
Flexural strength | MPa | 290 | 340 | 500 | 1000 | 820 | 600 | 320 | 420 | 430 | 850 | 750 | 70/30** | 450 |
Fracture toughness | MPam½ | - | 4.3 | 7.0 | 10.5 | 7.0 | 7.0 | - | 3.2 | 3.2 | 6.0 | 7.0 | - | - |
Elastic modulus* | GPa | 350 | 380 | 200 | 200 | 220 | 360 | 350 | 410 | 440 | 320 | 300 | 30/25** | 210 |
Weibull modulus* | - | 10 | 10 | 12 | 20 | 20 | 20 | 12 | 10 | 12 | 18 | 15 | - | - |
Poisson's ratio* | - | 0.22 | 0.22 | 0.3 | 0.3 | 0.27 | 0.24 | 0.22 | 0.17 | 0.16 | 0.26 | 0.25 | 0.13 | 0.33 |
Thermal properties | | | | | | | | | | | | | | |
max. Application temperature* under protective gas | °C | 1600 | 1650 | 900 | 1200 | 1200 | 1000 | 1350 | 1800 | 1800 | 1300 | 1300 | 2400 | 400 |
max. Application temperature* in air | °C | 1600 | 1650 | 900 | 1200 | 1200 | 1000 | 1350 | 1500 | 1500 | 1100 | 1100 | 850 | 300 |
Specific heat at 20°C | J/Kg K | 900 | 900 | 550 | 500 | 600 | 700 | 950 | 650 | 1000 | 750 | 700 | - | 462 |
Thermal conductivity at 100°C | W/mK | 25 | 30 | 2 | 2 | 6 | 25 | 85 | 75 | 90 | 35 | 35 | 35 | 50 |
Coefficient of thermal expansion(20°C - 1000°C) | 10-6K-1 | 8.5 | 8.5 | 10.5 | 10.5 | 9 | 9 | 4.5 | 4.1 | 4.1 | 3.2 | 3.3 | 2.2 | 11 |
Thermal shock resistance* | K | 180 | 190 | 260 | 300 | 300 | 250 | 400 | 350 | 450 | 400 | 450 | - | - |
Electrical properties | | | | | | | | | | | | | | |
Volume resistivity at 20°C | Ωcm | 1014 | 1014 | 1010 | 109 | 109 | 109 | 0.2 | 10-100 | 102 | 1010 | 1012 | 1014 | 0.0015 |
Volume resistivity at 400°C | Ωcm | 1011 | 1012 | 104 | 104 | 104 | 107 | - | - | - | - | - | - | - |
Volume resistivity at 1000°C | Ωcm | 104 | 107 | 103 | 103 | 102 | 105 | 0.05 | 0.2 | 0.2 | 107 | 107 | 109 | - |
Dielectric strength | kV/mm | >18 | >25 | - | - | - | - | - | - | - | - | - | 39 | - |
Dielectric constant at 20°C and 1 GHz | - | 8 | 9 | >20 | >20 | >20 | - | - | - | - | 20 | 20 | - | - |
Dielectric loss factor (tgΔ) at 20°C and 1 GHz | - | 5x10-4 | 2x10-4 | - | - | - | - | - | - | - | - | - | - | - |
Dielectric loss factor (tgΔ) at 20°C and 10 kHz | - | 3x10-4 | 1x10-4 | - | - | - | - | - | - | - | 5x10-2 | 5x10-2 | - | - |