refractory porous alumina ceramic disc for radiant heater
1.Material data
| Name | Alumina | Dense Cordierite | Porous Cordierite | Cordierite-Mullite | Mullite | Corundum mullite |
| Density(g/cm3) | 2.0~2.3 | 2.1 ~2.5 | 1.5 ~1.9 | 1.8~2.3 | 2.0 ~2.5 | 2.3 ~2.7 |
| Coefficient of heat expansion(×10-6K-1)(20~800°C) | ≤5 | ≤3.5 | ≤3.0 | ≤3.5 | ≤5 | ≤6 |
| Specific Heat (J/Kg.K)(20~1000°C) | 900~1150 | 900~1100 | 900~1100 | 900~1150 | 1000~1150 | 1100~1300 |
| Thermal Conductivity (W/m.k) (20~1000°C) | 1.5~2.0 | 1.5~2.5 | 1.2~1.8 | 1.5~2.0 | 1.5~2.0 | 1.5~2.5 |
| Impact Thermal Resistance(°C/min) | ≥300 | ≥300 | ≥350 | ≥350 | ≥350 | ≥300 |
| Max. Working Tem.(°C) | 1350 | 1300 | 1300 | 1320 | 1450 | 1550 |
| Water absorption(%) | 15-25 | ≤2 | 15~25 | 15 ~25 | 15~25 | 15 ~25 |
| Compressive strength(MPa) | ≥28 | ≥28 | ≥25 | ≥25 | ≥28 | ≥30 |
| Chemical composition (%) | Al2O3 | 55 ~65 | 25 ~38 | 28 ~38 | 40~52 | 60 ~70 | 70 ~80 |
| SiO2 | 25~35 | 50 ~60 | 45 ~55 | 45 ~55 | 25 ~35 | 15 ~25 |
| MgO | 1~3 | 5 ~10 | 11 ~14 | 7~9 | 0 ~1 | 0 ~2 |
| others | <5 | <5 | <5 | <5 | <5 | <5 |
2. Feature:
1). low thermal expansion
2). large specific heat capacity
3). high specific surface area
4). low pressure drop
5). small thermal resistance
6). good thermal conductivity
7). good heat-shock resisting ability
3. Application:
1)Electric appliance industry
2)Automotive industry
3)Mechanical industry
4)Engineer industry
