Aluminium Oxide, Al2O3 is a major engineering material. It offers a combination of good mechanical properties and electrical properties leading to a wide range of applications.
Alumina can be produced in a range of purities with additives designed to enhance properties. A wide variety of ceramic processing methods can be applied including machining or net shape forming to produce a wide variety of sizes and shapes of component. In addition it can be readily joined to metals or other ceramics using metallising and brazing techniques.
Alumina based ceramics are by far the largest range of advanced ceramics made by UNIPRETEC. Due to the important combination of properties, we have thoroughly researched the behaviour and characteristics of our Alumina products to give you the best possible component.
Typical Alumina characteristics include:
* Good strength and stiffness
* Good hardness and wear resistance
* Good corrosion resistance
* Good thermal stability
* Excellent dielectric properties (from DC to GHz frequencies)
* Low dielectric constant
* Low loss tangent
Typical Alumina applications include:
* Seal rings
* Medical prostheses
* Laser tubes
* Electronic substrates
* Ballistic armour
* Thermocouple tubes
* Electrical insulators
* Grinding media
* Threadguides
* Wear components
Characteristics | Unit | 95% Al2O3 | 99% Al2O3 | ZrO2 | GP-Si3N4 | HP-BN | Glass Ceramic |
Crystal Structure | - | hexagonal | hexagonal | tetragonal | hexagonal | hexagonal | - |
Color | - | white | ivory | white | gray | white | white |
Density | g/cm³ | 3.65 | 3.88 | 5.95 | 3.22 | 2.26 | 2.55 |
Water Absorption | % | 0 | 0 | 0 | 0 | 0.0-1.0 | 0 |
Young's Modulus | Gpa | 280 | 350 | 205 | 295 | 670 | 65 |
Vickers Hardness | Gpa | 14 | 20 | 12 | 18-20 | - | - |
Flexural Strength @R.T. | Mpa | 280 | 300 | 900 | 650 | 51 | 100 |
Compressive Strength @R.T. | Mpa | 2000 | 2500 | 2200 | 2200 | 23 | 500 |
Thermal Conductivity @R.T. | W/(m•K) | 18-25 | 30 | 2.2 | 25 | 20 | 1.70 |
Thermal shock resistance | ΔT(C°) | 220 | 180-200 | 280-350 | 450-650 | >1500 | 25-100 |
Max. Working Temperature @R.T. | C° | 1500 | 1700 | 850 | 1200 | 960 | 800 |
Volume Resistivity @R.T. | Ω・cm | >10^15 | >10^14 | >10^12 | >10^14 | 10^13 | 10^16 |
Dielectric Constant (1 MHz @R.T. ) | - | 9.50 | 9.80 | 26 | 8.20 | 4.08 | 6.02 |
Dielectric Strength | kV/mm | 16 | 22 | - | 16 | 375 | 40 |
