| | | Al2O3 content | % | 99.7 | 76 | 60 | - | - | - | - | - | | Alkali content | % | - | 0.5 | 3 | - | - | - | - | - | | SiC content | % | - | - | - | - | - | - | 88-92 | 99 | | Si-free | % | - | - | - | - | - | - | 8-12 | 0.1 | | Type according to DIN EN 60672 | - | C 799 | C 620 | C 610 | - | - | - | - | - | | Water absorption capacity | % | ≤0.2 | ≤0.2 | ≤0.2 | ≤0.2 | ≤0.2 | ≤0.2 | ≤0.1 | ≤0.1 | | Leakage rate at 20°C | hPa dm3s-1 | 10-10 | - | 10-10 | - | - | - | - | - | | Bulk density | g.cm-3 | 3.75-3.94 | 3 | 2.6 | 5.6 | 5.9 | 5.4 | 3.1 | 3.1 | | Flexural strength 20°C (3-point) | MPa | 300 | 150 | 120 | 500 | 800 | 200 | 240-280 | 350-400 | | Flexural strength 1300°C (3-point) | MPa | - | - | - | - | - | - | 250-300 | 370-420 | | Young’s modulus | GPa | 300-380 | 150 | 100 | - | - | - | 370 | 420 | | Hardness (Mohs scale) | - | 9 | 8 | 8 | - | - | - | - | - | | Thermal expansion 20-700°C | 10-6 K-1 | 7.8 | 5.6 | 5.4 | 9.8 | 10.6 | 9.9 | 3.7 | - | | Thermal expansion 20-1000°C | 10-6 K-1 | 8.6 | 6 | 6 | 10.3 | 10.9 | - | 4.3 | 5 | | Thermal conductivity 200°C | Wm-1K-1 | 25 | 6 | 2 | - | - | - | 100 | 124 | | Maximal approximate temp for load-bearing elements3 | °C | 1700 | 1600 | 1400 | 1500 | 1000 | 2000 (w/o load) | 1350 | 16004 | | Dielectric strength (IEC 672-2) | kV.mm-1 | 17 | 17 | 17 | - | - | - | - | - | | Resistivity at DC voltage 20°C | Ω.cm | 1014 | 1013 | 1013 | - | - | - | - | - | | Thermal shock resistance | - | good | excellent | good | good | good | - | good | excellent | | Diameter of pores, av | µm | - | - | - | - | - | - | - | - | | Specific heat capacity 20-100°C | J.kg-1.K-1 | 990 | 900 | 900 | - | - | - | - | - | Properties of Porous Materials | | | Al2O3 content | % | 99.5 | 72-74 | 78-80 | 72-74 | 70 | - | - | - | - | | Alkali content | % | - | 1 | 1 | 1 | 1 | - | - | - | - | | SiC content | % | - | - | - | - | - | 70-90 | 99 | 99 | - | | Si-free | % | - | - | - | - | - | - | 0.1 | 0.1 | - | | Type according to DIN EN 60672 | - | - | C 530 | - | - | - | - | - | - | - | | Water absorption capacity | % | 2.7 | 9 | 11 | 6 | 9 | 8-13 | 5 | 5 | 4.6 | | Leakage rate at 20°C | hPa dm3s-1 | - | - | - | - | - | - | - | - | - | | Bulk density | g.cm-3 | 3.6 | 2.40-2.45 | 2.45-2.50 | 2.60 | 2.40-2.45 | 2.2-2.5 | 2.7 | 2.7 | 1.92-2 | | Flexural strength 20°C (3-point) | MPa | 70-110 | 45 | 55 | 60 | 45 | 30 | 80-100 | 80-90 | 30-40 | | Flexural strength 1300°C (3-point) | MPa | - | - | - | - | - | - | 90-110 | 90-110 | 45-602 | | Young’s modulus | GPa | - | 60 | 75 | 85 | 60 | - | 280 | 280 | 30-40 | | Hardness (Mohs scale) | - | - | - | - | - | - | - | - | - | - | | Thermal expansion 20-700°C | 10-6 K-1 | 7.8 | 5.3 | 5.3 | 5.2 | 5.3 | 5 | 3.9 | 3.9 | - | | Thermal expansion 20-1000°C | 10-6 K-1 | 8.6 | 5.7 | 6.3 | 5.7 | 5.7 | 5 | 4.5 | 4.5 | 0.5-0.9 | | Thermal conductivity 200°C | Wm-1K-1 | - | 1.4 | 1.4 | - | 1.4 | - | 35 | 35 | - | | Maximal approximate temp for load-bearing elements3 | °C | 1700 | 1350 | 1400 | 1600 | 1350 | 1300 | 16004
20005 | approx 16504 | 1000 | | Dielectric strength (IEC 672-2) | kV.mm-1 | - | - | - | - | - | - | - | - | - | | Resistivity at DC voltage 20°C | Ω.cm | - | - | - | - | - | - | - | - | - | | Thermal shock resistance | - | good | excellent | excellent | good | excellent | excellent | excellent | excellent | excellent | | Diameter of pores, av | µm | 1-3 | 2 | 1.5 | 8.5 | 2 | 3 | 24 | 24 | 0.2 | | Specific heat capacity 20-100°C | J.kg-1.K-1 | - | 800 | 900 | 900 | - | - | - | - | - | The values listed above pertain to test specimens. They are for reference purposes only and cannot be applied unconditionally to other shapes and dimensions. In practice, Alsint 99.7 components show mechanical strength values between 160 and 300 MPa, depending on their wall thickness, actual shape, surface finish, shaping process, and post-processing. 1since different qualities are available (and for reference purposes only) 2at 700°C 3dependent upon load 4under oxidizing conditions 5under inert atmosphere |