Alumina (aluminum oxide, Al₂O₃) is the cornerstone of our ceramic solutions—a remarkable material that combines exceptional hardness with outstanding electrical insulation properties. At Freecera, we work with various grades of alumina ceramics, ranging from 94% to 99.8% purity, each offering distinct advantages for specific applications. This versatile material exhibits excellent thermal conductivity while maintaining strength at high temperatures, making it ideal for components that face demanding operational conditions. Its chemical inertness means our alumina ceramics resist corrosion from acids, alkalis, and other aggressive substances that would quickly degrade metals or polymers. We’ve perfected the art of precision-forming this remarkable material into complex shapes while maintaining tight tolerances, ensuring that every component we deliver meets your exact requirements for performance and longevity.
| Properties | Test Conditions | Unit | Results |
| Alumina Content | % | 99.8 | |
| Color | Beige | ||
| Bulk Density | g/cm3 | 3.89 | |
| Water-absorption | % | 0 | |
| Grain size | μm | 4-5 | |
| Vickers Hardness, HV1.0 | Load 4.9N | GPa | ≥15 |
| Flexural Strength, RT | MPa | ≥300 | |
| Coefficient of Linear Expansion | 20～500℃ | 1×10-6mm/℃ | 6.5～7.5 |
| 20～800℃ | 6.5～8.0 | ||
| Thermal Conductivity, RT | 20℃ | W/m·K | ≥20.9 |
| Specific Heat Capacity | kJ/(kg·K) | ≥0.8 | |
| Dielectric Strength | KV/mm | ≥12 | |
| Electrical Resistivity, RT | 20℃ | Ohm.cm | ≥1014 |
| 300℃ | ≥1011 | ||
| 500℃ | ≥109 | ||
| Permittivity | 1MHz | 9～10 | |
| Dielectric Dissipation Factor | 1MHz | ≤3×10-4 | |
| Surface Roughness | μm | Processable to 0.1～0.4 |
| Ingredients | Unit | Value |
| Na2O | % | 0. 09 |
| Fe2O3 | % | 0. 0164 |
| SiO2 | % | 0. 0249 |
| MgO | % | 0. 0953 |
| CaO | % | 0. 021 |
| Chemistry by ICP | ||
| Green Density | g/cm3 | 2. 33 |
| Density with Weber press | ||
| Fired Density | g/cm3 | 3. 90 |
| Fired Density 1600°C SDP | ||
| Shrinkage | % | 16.3 |
| Shrinkage SDP |
At Freecera, we pride ourselves on crafting exceptional custom alumina ceramics that combine precision with durability. Our high-purity alumina solutions are fully engineered to your exact specifications, offering superior thermal stability and electrical insulation that consistently exceeds industry standards. We understand that your applications demand materials that perform under pressure—whether in extreme temperatures, corrosive environments, or high-wear conditions—which is why our team works closely with you from concept to completion. With decades of ceramic expertise behind us, we don’t just manufacture components; we develop lasting partnerships that help transform your most challenging design requirements into reliable, high-performance ceramic solutions you can count on day after day.
