Aluminum Oxide, Alumina (Al2O3)
Alumina, also known as aluminum oxide, is the most widely used technical ceramic due to its excellent electrical insulation, high hardness, wear resistance, chemical stability, and high-temperature performance.
Advanced Ceramic Materials (ACM) supplies alumina ceramics in multiple purity grades, including 95%, 99%, 99.5%, and 99.7% alumina. We provide standard alumina components such as tubes, rods, plates, crucibles, and custom ceramic parts for electronic, semiconductor, industrial, and high-temperature applications.
Compare alumina grades and properties below, or explore our alumina ceramic products to find the right material for your application.
More Info About Alumina
Products | Specification | Applications | FAQs | Brochure
- Excellent electrical insulation
- High hardness and wear resistance
- Good thermal conductivity
- High-temperature stability
- Excellent chemical corrosion resistance
- Cost-effective compared with many advanced ceramics
- Available in multiple purity grades
| Material | Alumina | ||||
| Properties | Units | AL997 | AL995 | AL99 | AL95 |
| %Alumina | - | 99.70% | 99.50% | 99.00% | 95.00% |
| Color | - | Ivory | Ivory | Ivory | Ivory & White |
| Permeability | - | Gas-tight | Gas-tight | Gas-tight | Gas-tight |
| Density | g/cm3 | 3.94 | 3.9 | 3.8 | 3.75 |
| Straightness | - | 1‰ | 1‰ | 1‰ | 1‰ |
| Hardness | Mohs Scale | 9 | 9 | 9 | 8.8 |
| Water Absorption | - | ≤0.2 | ≤0.2 | ≤0.2 | ≤0.2 |
| Flexural Strength(Typical 20℃) | Mpa | 375 | 370 | 340 | 304 |
| Compressive Strength (Typical 20℃) |
Mpa | 2300 | 2300 | 2210 | 1910 |
| Coefficient of Thermal Expansion (25℃ to 800℃) |
0-6/℃ | 7.6 | 7.6 | 7.6 | 7.6 |
| Dielectric Strength (5mm Thickness) | AC-kv/mm | 10 | 10 | 10 | 10 |
| Dielectric Loss 25ºC@ 1MHz |
- | < 0.0001 | < 0.0001 | 0.0006 | 0.0004 |
| Dielectric Constant | 25º C@ 1MHz | 9.8 | 9.7 | 9.5 | 9.2 |
| Volume Resistivity (20℃) (300℃) |
Ω·cm³ | >1014 2*1012 |
>1014 2*1012 |
>1014 4*1011 |
>1014 2*1011 |
| Long-term Operating Temperature | ℃ | 1700 | 1650 | 1600 | 1400 |
| Thermal Conductivity (25℃) | W/m·K | 35 | 35 | 34 | 20 |
Alumina ceramics stand out for their versatility across a broad spectrum of applications, from high-tech engineering and semiconductor manufacturing to traditional industries and medical prosthetics.
Read more: Everything You Need to Know about Alumina Ceramics
ACM's product formulations are developed to address a range of application problems. Many industrial applications push the envelope on specific requirements, leading to the development of new formulations.
| Properties | Unit | Fused Alumina | Reactive Grade Alumina | Ready To Press Alumina (RTP Alumina) | Activated Alumina | |||||||
| Al2O3 Content | % | 95.5 | 99.8 | 98 | 96 | 94 | 92 | 90 | ||||
| Bulk Density | g/cm3 | 3.95 | ~600 | ~1000 | ~600 | ~1100 | ~900 | ~1200 | ~1100 | – | ||
| Grain Size | μm | Customized | Customized | ≈130 | ≈170 | ≈100 | ≈200 | customized | ||||
| Color | – | White | White | White | White | |||||||
| Melting Point | ℃ | 2000 | – | – | – | |||||||
| Hardness | Mohs | 9 | – | – | – | |||||||
| Specific Surface Area | m2/g | – | 0.2-0.5 | 3.5-5 | 2-3 | 6-9 | 6-10 | – | 200-260 | |||

Advanced Ceramic Materials (ACM) is a leading supplier of high-quality alumina ceramic products for a range of applications. We are happy to provide advice on materials, design, and application. Feel free to contact us with questions about Al₂O₃ or other ceramic materials not listed on the website.
| Chemical Formula | Al2O3 |
| Mechanical | |
| Density | 3.9 g/cm3 |
| Hardness | 17.2 GPa |
| Modulus of Elasticity | 380 GPa |
| Flexural Strength | 380 MPa |
| Compressive Strength | 2450 MPa |
| Poisson's Ratio | 0.23 |
| Fracture Toughness | 4 MPa m½ |
| Electrical | |
| Dielectric Strength | 15 ac V/mm |
| Dielectric Constant | 9.9 (@ 1 MHz) |
| Volume Resistivity | 10^14 ohm-cm |
| Thermal | |
| Coefficient of Thermal Expansion | 7.2 x 10^-6/°C |
| Thermal Conductivity | 20 - 35 W/(m*K) |
| Specific Heat | 780 J/(Kg*K) |
| Shock Resistance | 250 °C Diff. |
| Maximum Working Temperature | 1700 °C |