Materials
High-alumina and corundum material data.
Two alumina families cover most of what we make. The values below are typical properties for each material. Temperature and purity belong to a grade, not to every product.
Material datasheet
- High-alumina ceramic
- Al₂O₃ >85 %
- High-purity alumina / corundum ceramic
- Al₂O₃ 99 / 99.5 / 99.7 %
| Property | Unit | High-alumina | Corundum |
|---|---|---|---|
| Composition | |||
| Al₂O₃ content | % | >85 | 99-99.5* |
| SiO₂ content | % | <12 | <0.2 |
| Fe₂O₃ content | % | <0.2 | <0.05-0.1 |
| Thermal and mechanical | |||
| Working temperature | °C | 1300–1450 | 1600–1800* |
| Hardness (Mohs) | 8 | 8-9 | |
| Water absorption | % | <0.2 | ≤0.2 |
| Bulk density | |||
| Bulk density, slip cast | g/cm³ | 3.6-3.7 | 3.7-3.9 |
| Bulk density, pressed or extruded | g/cm³ | 3.5-3.65 | 3.65-3.8 |
| Bulk density, hot pressed | g/cm³ | 3.5-3.7 | 3.7-3.85 |
| Rupture strength, room temperature | |||
| Rupture strength, slip cast | MPa | 190 | 200 |
| Rupture strength, pressed | MPa | 140 | 150 |
* Stated per SKU. Not every corundum product is 99.7% Al₂O₃ or suitable for 1800 °C; the grade and maximum temperature of each part are confirmed in its quotation.
Notes on these values
Corundum grades
Property data apply to the 99–99.5% grades. 99.7% is available, with properties confirmed per part.
Per SKU
Purity and maximum temperature are stated for each product. Not every corundum product is 99.7% Al₂O₃, and not every corundum product is suitable for 1800 °C.
Contractual datasheets
Values are typical. A datasheet for the ordered grade comes with each quotation, with product-specific test data, dimensions and tolerances.
Properties
What alumina ceramics are chosen for
Which of these apply depends on the grade and the part.
- High-temperature resistance
- High mechanical strength
- Good thermal conductivity
- Thermal-shock resistance
- High softening temperature
- High-temperature electrical insulation
- High-frequency electrical performance
- Acid and alkali resistance
- Chemical corrosion resistance
- Wear resistance
- Low contamination for appropriate high-purity grades
Other materials
Also available on request
We also make parts in these materials. Property data is supplied with the quotation.
- Mullite ceramic
- Partially stabilized zirconia
- Steatite ceramic
- Cordierite ceramic
- Wollastonite ceramic
- Chrome-corundum ceramic
Request a quote
Not sure which grade you need? Tell us the temperature and atmosphere.
Tell us the dimensions, grade and quantity. A contractual datasheet with current, product-specific test data and tolerances comes with each quotation.
- Custom parts, usually from
- 100 pcs
- Samples for approval
- 5–10 pcs
- Production, usually
- 25–30 days
- Standard sizes from stock, small to bulk orders
- ~3–7 days