Great mechanical strength
Low thermal conductivity
High heat resistance
Small thermal expansion coefficient
Good cold-resistance heat-resistance
Resistance to acid and alkali corrosion
Technical Index
| AL2O3% Composition | Density
(g/cm3) |
Flexural Strength
(MPa) |
Thermal Conductivity [w/(m.R)] |
Dielectric Strength (KV/mm) |
Working Temp. |
| 60 | 3.0 | 205 | 16 | 10 | 1000°C |
| 75 | 3.1 | 280 | 17 | 10 | 1250°C |
| 80 | 3.3 | 215.7 | 17 | 10 | 1290°C |
| 85 | 3.4 | 230 | 17 | 10 | 1350°C |
| 92 | 3.6 | 312 | 18 | 10 | 1390°C |
| 95 | 3.7 | 304 | 20 | 10 | 1480°C |
| 99 | 3.81 | 340 | 34 | 10 | 1600°C |
| 99.7 | 3.85 | 370 | 35 | 10 | 1700°C |
| Chemical
competent |
Al2O3 | ≥99.5% |
| SiO2 | <0.2% | |
| Fe2O3 | <0.1% | |
| Alkaline matter | <0.1% | |
| Density | 3.9 g/cm3 | |
| Hardness | 9 M | |
| Water absorption | <0.1% | |
| Rupture strength | >2000kg/cm2 | |
| Gas tightness | Kept for ten minutes at negative pressure of 1.3Kpa. The pressure drop is less than 0.3Kpa. | |
| Thermal tolerance | Insert the pipe into the furnace at a depth of 20mm. Heat to 1600℃ and maintain for 30 minutes. | |
| Alkali tolerance | In the Na2CO3 solution of 2N concentration, boil for 15 hours with the weight loss not greater than 20mg/dm2. | |
| Volume resistance | >9*10(5) Ω·cm/1600℃ | |
| Breakdown voltage | 20kv/cm | |
| Expansion coefficient | 8*10(-8) | |
| Temperature for use | Long-term: 1600℃ Short-term: 1800℃ | |
| Chill and abrupt heat | 1500℃~room temperature not cracking thrice. | |
