Alumina ceramic is the most widely used technical ceramic materials. It has high wear resistance, high mechanical strength, high temperature resistance, good thermal shock resistance, excellent electrical insulation. It is usually used for electrical insulators, wear resistant parts, ceramic parts for high temperature furnace.
Alumina ceramic insert can be made by different purities like 95%, 96%, 99%, 99.5%, 99.7%, their properties will have little difference accordingly.
| Operating Limits | Units | Alumina Ceramics | Alumina Ceramics |
| Alumina Content | wt% | ≥ 99 | ≥ 95 |
| Volume Density | G /CM3 | 3.85 | 3.70 |
| Hardness (HRA) | HRA ≥ | 88 | 86 |
| Compressive Strength | MPa ≥ | 400 | 300 |
| Maximum Temperature | ℃ | 1500 | 1500 |
| Air Tight Test | Pass | Pass | |
| Thermal Shock Test | Pass | Pass | |
| Coefficient Of Heat Expansion | ×10-6/℃ | 8.2 | 7.5 |
| Dielectric Constant | εr20℃, 1MHz | 9.2 | 9.0 |
| Dielectric Loss | tanδ×10-4, 1MHz | 2 | 3 |
| Volume Resistivity | Ω·cm 20℃ | 1014 | 1013 |
| Puncture Strength | KV/mm , DC≥ | 20 | 20 |
| Acid-resistance | mg/cm2 ≤ | 0.7 | 7.0 |
| Alkali-resistant | mg/cm2 ≤ | 0.1 | 0.2 |
| Abrasion Resistance | g/cm2 ≤ | 0.1 | 0.2 |
| Compressive Strength | M Pa ≥ | 2800 | 2500 |
| Flexural Strength | M Pa ≥ | 350 | 200 |
| Elastic Modulus | G Pa | 350 | 300 |
| Poisson's Ratio | 0.22 | 0.20 | |
| Thermal Conductivity | W/m·K( 20℃) | 25 | 20 |
