99% Alumina ceramic is used to make high-temperature crucible, furnace tube and special wear-resistant materials, such as ceramic bearing, ceramic seal and water valve sheet, etc.
95% alumina ceramic is mainly used as corrosion-resistant and wear-resistant parts.Due to the addition of talc, the electrical properties and mechanical strength are improved, which can be sealed with molybdenum, niobium, tantalum and other metals, and some are used as electrical vacuum devices.
Alumina ceramics are currently classified into high-purity and ordinary types. High-purity alumina ceramics are ceramic materials with Al2O3 content above 99.9%; due to their sintering temperature as high as 1650-1990 ° C, the transmission wavelength is 1 ~ 6 & mu; m, generally made of molten glass to replace platinum crucible; Translucent and alkali-resistant metal corrosion are used as sodium lamps;
they can be used as integrated circuit substrates and high-frequency insulation materials in the electronics industry. Ordinary alumina ceramics are classified into 99 porcelain, 95 porcelain, 90 porcelain, 75 porcelain, etc. according to the content of Al2O3. Sometimes the Al2O3 content is 80%; or 75% is also classified as ordinary alumina ceramic series.
Alumina Ceramic Parameters:
| Ability | Unit | Alumina AL2O3 |
| Bulk density | g/cm3 | 3.85-3.93 |
| hardness | HRA≥ | 86 |
| Bending strength | Mpa≥ | 300 |
| Maximum use temperature | ℃ | 1500 |
| Linear expansion coefficient | ×10-6/℃ | 7.15-7.67 |
| Dielectric constant | εr(20℃,1MHz) | 9.21 |
| Dielectric loss | tanδ×10-4,1MHz | 2.5 |
| Volume resistivity | Ω·cm(100℃) | 9.2*1016 |
| Compressive strength | Mpa≥ | 2500 |
| Flexural strength | Mpa≥ | 200 |
| Elastic Modulus | Gpa | 300 |
| Poisson's ratio | 0.2 | |
| Thermal Conductivity | W/m·K(20℃) | 20 |
| DC breakdown strength | KV/mm | 43.7 |
| Tensile seal strength | Mpa | 104.4 |
