Aluminum Oxide (Alumina)
Material Information
Specifications
General Properties | Alumina 96% | Alumina 99.5% | Alumina 99.8% |
---|---|---|---|
Density - gm/cc | 3.72 | 3.9 | 3.92 |
Crystal Size (Average) - Microns | 6 | 6 | 6 |
Water Absorbtion (Open Porosity) - % | 0 | 0 | 0 |
Gas Permeability - % | 0 | 0 | 0 |
Color | White / Pink | Ivory | Ivory |
Mechanical Properties | Alumina 96% | Alumina 99.5% | Alumina 99.8% |
---|---|---|---|
Flexural Strength (MOR) 20°C - Mpa (psi x 10³) | 358 (52) | 379 (55) | 375 (54) |
Elastic Modulus 20°C - GPa (psi x 10⁶) | 303 (44) | 370 (54) | 370 (54) |
Poisson’s Ratio 20°C | 0.21 | 0.22 | 0.22 |
Compressive Strength 20°C - MPa (psi x 10³) | 2068 (300) | 2600 (377) | 2500 (363) |
Hardness - GPa (kg/mm²) | 11.5 (1175) | 14.1 (1440) | 14.1 (1440) |
Hardness - R45N | 78 | 83 | 83 |
Tensile Strength 25°C - MPa (psi x 10³) | 221 (32) | 262 (38) | 248 (36) |
Fracture Toughness K(I c) - mpa m½ | 5-Apr | 4.5 | 5-Apr |
Electrical Properties | Alumina 96% | Alumina 99.5% | Alumina 99.8% |
---|---|---|---|
Dielectric Strength 6.35mm - ac-kV/mm (ac V/mil) | 8.3 (210) | 8.7 (220) | 8.7 (220) |
Dielectric Constant 1 MHz - 25°C | 9 | 9.7 | 9.8 |
Dielectric Loss (tan delta) 1 MHz - 25°C | 0.0002 | 0.0001 | <0.0001 |
Volume Resistivity 25°C - ohm-cm | >10 | ||
Volume Resistivity 500°C - ohm-cm | |||
Volume Resistivity 1000°C - ohm-cm |
Thermal Properties | Alumina 96% | Alumina 99.5% | Alumina 99.8% |
---|---|---|---|
Thermal Conductivity 20°C - W/m K | 24.7 | 30 | 30 |
Coefficient of Thermal Expansion 25-1000°C - X 10-6/°C | 8.2 | 8.2 | 832 |
Specific Heat 100°C - 880 J/kg*K | 880 | 880 | 880 |
Thermal Shock Resistance ΔTc - °C | 250 | 200 | 200 |
Maximum Use Temperature - °C | 1700 | 1750 | 1750 |
NOTE: The information in this data sheet is for design guidance only. Forming methods and specific geometry could affect properties.
Overview
Alumina is properly called aluminum oxide, which is a chemical compound comprised of aluminum and oxygen molecules (Al2O3). When refined from bauxite, alumina generally looks like a white powder similar to table salt or granular sugar. Aluminum oxide is typically referred to as alumina, but may also be called aloxide, aloxite or alundum, depending on the industry and the metal’s use. In addition to its use in the production of primary aluminum, aluminum oxide has other key industrial uses. Alumina is often used as a filler for plastics. The compound is also widely used as an abrasive and is a less-expensive substitute for industrial diamond. Aluminum oxide flakes produce reflective effects within the paint used on automobiles. The largest scale use of alumina occurs in refineries, where the aluminum oxide compound is used to convert dangerous hydrogen sulfide waste gases into elemental sulfur. Data provided by The Aluminum Association and Ortech Advanced Ceramics.
Applications & Usage
- Repeller Insulators
- Ceramic Fasteners
- Spindle Fork Fingers
- Ball Joints
- Dental Cements
- Toothpaste
- Sunscreen
- Abrasive component in sandpaper, grinders, polishers, and microdermabrasion
- Integrated Circuits
- Compact Fluorescent Lamps
- Reflective Paint