Alumina
Alumina (Al2O3) is one of the most widely used, general purpose technical ceramics. Alumina provides several benefits including being extremely hard and wear resistant across a wide temperature range. Alumina is produced by heating tightly packed alumina powder with a binder material. This process produces commercial grades of 90 - 99.95%, with higher purity providing higher hardness.
90%-97% Alumina: most suitable for metal deposition due to its large grain structure.
98%-99.95% Alumina: Commonly available for extruded shapes at low cost.
Zirconia Toughened Alumina (ZTA): is a material that is tougher than Alumina with improved hardness, strength and thermal properties especially at high temperatures.
Alumina applications:
- Pump piston sleeves
- Bushings & insulators
- Impellers
- Valve seals & seats
- Medical implants
- Die & cutting tool inserts
- Bearing components
We can machine Alumina into a variety of sheets, cylinders, discs and other complex shapes.
| Property | Value |
|---|---|
General |
|
| Chemical Formula | Al2O3 |
Mechanical |
|
| Density | 3.88 g/cm3 |
| Hardness | 2000 Knoop |
| Modulus of Elasticity | 48 - 54 x 106 psi |
| Flexural Strength | 57 kpsi |
| Compressive Strength | 368 kpsi |
| Poisson's Ratio | 0.23 - 0.26 |
| Fracture Toughness | 4.3 MPa m1/2 |
Electrical |
|
| Dielectric Strength | 210 - 220 ac V/mil |
| Dielectric Constant | 9.7 (@ 1MHz) |
| Volume Resistivity | >1014 Ohm-cm |
Thermal |
|
| Coefficient of Thermal Expansion | 5.1 - 7.2 x 10-6/°C |
| Thermal Conductivity | 30.3 - 35.0 W/mK |
| Specific Heat | 0.20 cal/g °C |
| Shock Resistance | 200°C Diff |
| Maximum Working Temperature | 1750 °C |