Silicon Carbide Seals
Silicon Carbide | |||||
Material properties | Norm | Symbol/Unit | F | F plus | T |
Density | DIN EN 623-2 | ρ [g/cm3] | >3.10 | >3.16 | >3.21 |
Porosity | DIN EN 623-2 | P [%] | <3.0 | <1.0 | <1.0 |
Mean grain size | [μm] | <5 | <5 | <2 | |
Grain size distribution | [μm] | ||||
Phase composition | α-SiC | α-SiC | α-SiC, YAG |
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Vickers hardness | DIN EN 843-4 | HV 1 [GPa] | 25.5 | 25.5 | 22.5 |
Knoop hardness | DIN EN 843-4 | HK 0.1 [GPa] | 24.5 | 24.5 | 21.0 |
Young's modulus | DIN EN 843-2 | E [GPa] | 410 | 420 | 420 |
Weibull modulus | DIN EN 843-5 | m | 10 | 15 | 15 |
Flexural strength, 4-pt bending |
DIN EN 843-1 | σB [MPa] | 400 | 510 | 550 |
Compressive strength | σD [MPa] | 2200 | 2200 | 2500 | |
Poisson ratio | ν | 0.17 | 0.17 | 0.16 | |
Fracture toughness (SENB) |
Klc [MPa·m0,5] | 4 | 4 | 6 | |
Coefficient of thermal expansion |
DIN EN 821-1 | ||||
20°C - 500°C | α [10-6/K] | 4.1 | 4.1 | 3.5 | |
500°C - 1000°C | α [10-6/K] | 5.2 | 5.2 | 5.2 | |
Specific heat at 20°C | DIN EN 821-3 | cp [J/g K] | 0.6 | 0.6 | 0.6 |
Thermal conductivity at 20°C |
DIN EN 821-2 | λ [W/mK] | 125 | 125 | 75 |
Thermal stress parameters |
calculated | ||||
R1 = σB·(1-ν) / (α·E) | R1 [K] | 198 | 246 | 314 | |
R2 = R1·λ | R2 [W/mm] | 25 | 31 | 24 | |
Specific electrical resistance at 20°C |
DIN EN 50359 | ρ [Ω cm] | 106-108 | 106-108 | 102-103 |
Silicon Carbide | |||||
Material properties | Norm | Symbol/Unit | C | P | G |
Density | DIN EN 623-2 | ρ [g/cm3] | >3.10 | >2.76- 2.89 |
>3.02 |
Porosity | DIN EN 623-2 | P [%] | <3.0 | 10-14 | <3.0 |
Mean grain size | [μm] | bimodal | <5 | bimodal | |
Grain size distribution | [μm] | 10-1500 | 10-1000 | ||
Phase composition | α-SiC | α-SiC | α-SiC, graphite |
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Vickers hardness | DIN EN 843-4 | HV 1 [GPa] | 25.5 | 23.5 | 24.5 |
Knoop hardness | DIN EN 843-4 | HK 0.1 [GPa] | 24.5 | 21.6 | 23.0 |
Young's modulus | DIN EN 843-2 | E [GPa] | 410 | 340 | 390 |
Weibull modulus | DIN EN 843-5 | m | 10 | 15 | 14 |
Flexural strength, 4-pt bending |
DIN EN 843-1 | σB [MPa] | 400 | 225 | 230 |
Compressive strength | σD [MPa] | 2500 | 2000 | 2500 | |
Poisson ratio | ν | 0.17 | 0.17 | 0.16 | |
Fracture toughness (SENB) |
Klc [MPa·m0,5] | 3.5 | 3 | 3 | |
Coefficient of thermal expansion |
DIN EN 821-1 | ||||
20°C - 500°C | α [10-6/K] | 4.1 | 3.5 | 4.0 | |
500°C - 1000°C | α [10-6/K] | 5.2 | 5.6 | 5.0 | |
Specific heat at 20°C | DIN EN 821-3 | cp [J/g K] | 0.6 | 0.6 | 0.6 |
Thermal conductivity at 20°C |
DIN EN 821-2 | λ [W/mK] | 125 | 90 | 110 |
Thermal stress parameters |
calculated | ||||
R1 = σB·(1-ν) / (α·E) | R1 [K] | 198 | 157 | 124 | |
R2 = R1·λ | R2 [W/mm] | 25 | 14 | 14 | |
Specific electrical resistance at 20°C |
DIN EN 50359 | ρ [Ω cm] | 103-104 | 106-108 | 103-104 |