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Aluminum Oxide, Alumina (Al2O3)

Aluminum Oxide, Alumina (Al2O3)

Alumina (Al₂O₃) is the most widely used technical ceramic. With a melting point of 2072°C, high electrical insulation, good thermal conductivity (20–35 W/m·K), excellent wear resistance, and strong chemical resistance, it is an indispensable material across industries.

Its low thermal expansion and mechanical strength allow components to endure extreme conditions and mechanical stress. From electronics to mechanical systems, alumina's multifaceted performance makes it a key material in modern industry and technological innovation.

We offer alumina in four purity grades: 95%, 99%, 99.5%, and 99.7%. Use the table below to compare their properties, or browse our product list to find the right part for your application.

Need a specific purity? Check the comparison table for 95% / 99% / 99.5% / 99.7% below, then scroll to Products to find ready-to-buy or custom parts.

More Info About Alumina

Products | Specification | Applications | FAQs | Brochure

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Aluminum Oxide Specifications

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

Aluminum Oxide Applications in Various Industries

  1. Industrial Appliances – Furnaces, thermocouple protectors
  2. Coatings – Abrasion, corrosion, and thermal shock protection
  3. Labware – Crucibles, mortars, pestles
  4. Engineered Ceramics – CVD, ion implants, photolithography, semiconductor manufacturing
  5. Refractories – Furnace and kiln linings
  6. Artificial Bones and Joints – Biocompatible medical implants
  7. Abrasives – Grinding media, abrasive tools
  8. Consumer Electronics – Insulators, substrates, enclosures
  9. Traditional Industry – Injector tubes, gas nozzles, insulators
  10. Grinding and Polishing Tools – Laboratory sample preparation

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

Aluminum Oxide Formulations

ACM's product formulations are developed to address varied 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
Al2OContent % 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

Corundum vs. Alumina vs. Cordierite vs. Mullite

ACM Ceramic Product Categories

Your Aluminum Oxide Ceramics Supplier

Advanced Ceramic Materials (ACM) is a leading supplier of high-quality alumina ceramic products for various 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.

Related Documents
95% to 99.7% purity grades, properties, and applications
Particle size, purity, and thermal filler applications
FAQs
How Are Alumina Components Made?

Alumina components are typically manufactured through processes such as dry pressing, isostatic pressing, injection molding, slip casting, and extrusion. After forming, the parts are sintered at high temperatures (typically 1600-1800°C) to achieve full density and mechanical strength.

Do You Supply Customized Al2O3 Components?

We can supply customized products according to the drawings you provide, and our engineers can also provide technical support and advice for your design.

What Are the Characteristics of Aluminum Oxide?

Aluminum Oxide is characterized by high hardness, excellent resistance to corrosion, thermal stability, good dielectric properties (for converting from DC to GHz frequencies), low loss tangent, and stiffness. See the next section for more details on the properties of alumina ceramic materials.

What Are the Different Types of Aluminum Oxide Ceramic?

Depending on the content of Al2O3 and additives used, there are different series of aluminum oxide mateials. Based on the Al2O3 content, alumina can be categorized as 75% alumina, 85% alumina, 95% alumina, 99% alumina, and so on. Based on the difference in crystal phase, there are mullite, corundum-mullite, and corundum; Based on the variety of additives used, there is the chromium corundum, titanium corundum, etc.

What Are the Differences Between Zirconia Toughened Alumina (zta) and Alumina Toughened Zirconia (atz)?

While both ZTA and ATZ have the same raw materials, it is important not to confuse the two composites. In alumina toughened zirconia (ATZ), the ratio of alumina to zirconia is low. In zirconia toughened alumina (ZTA), the opposite is the case.

96% vs 99% Alumina — Which One Should I Choose?

96% alumina is suitable for most general industrial applications where cost is a consideration. 99% and above is recommended for semiconductor processing, high-voltage electronics, and medical implants where purity and reliability are critical.

How Does Alumina Compare to Other Ceramic Materials?

Alumina offers a superior combination of hardness, thermal stability, and chemical resistance compared to many other ceramic materials, making it more versatile and widely applicable in various industries.

Is Alumina Environmentally Friendly?

Alumina is inert and non-toxic, posing minimal environmental impact. Its durability and recyclability further contribute to its environmental friendliness in various applications.

Properties
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 37 W/(m*K)
Specific Heat 780 J/(Kg*K)
Shock Resistance 250 °C Diff.
Maximum Working Temperature 1700 °C
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