Advanced ceramics refer to materials, which exhibit superior mechanical and physical properties. These include superior corrosion/oxidation resistance, and thermal, electrical, optical or magnetic properties. Advanced ceramics generally include structural ceramics, electronic ceramics, ceramic coatings, and bio-ceramics.The varieties of Advanced ceramics materials include:
Aluminum Oxide(Al2O3)
Aluminum Oxide (Al2O3) a is the most well-known and cost-effective ceramic material. Due to a combination of good strength, a high E-module and thermal shock resistance you can find it in high-temperature applications such as protective tubes, as well those where low friction is required i.e. slide bearings in pumps. The good hardness and the excellent temperature durability (max. operation temperature 1,500°C) makes Aluminum Oxide a reliable partner.
Zirconium Oxide(ZrO2)
Zirconium(di)oxide (ZrO2) is favoured in wide range of mechanical and forming applications as it has the highest fracture toughness of the oxide ceramic materials. It also possesses very good high temperature properties and can be joined directly to steel due to the compatible coefficients of expansion. Due to its excellent biocompatibility, strength and translucency, zirconia is increasingly used in the construction for zirconium oxide products like crowns and bridges in dentistry.
Boron Nitride(BN)
Boron Nitride is a synthetic technical ceramic material, which is available in powder, solid, aerosol and liquid forms. It has out-standing thermal characteristics; high thermal conductivity and excellent thermal shock resistance and is stable in inert and reducing atmospheres up to 2000°C, and in oxidizing atmospheres to 850°C. In its solid form, Boron Nitride can easily be machined to close tolerances in virtually any shape. After machining, it is ready for use without additional heat treating or firing operations.
Silicon Nitride(Si3N4)
Silicon nitride is dark gray to black in color and can be polished to a very smooth reflective surface, giving parts with a striking appearance. High performance silicon nitride materials were developed for automotive engine wear parts, such as valves and cam followers and proven effective. The cost of the ceramic parts never dropped enough to make the ceramics feasible in engines and turbochargers. The very high quality bodies developed for these demanding high reliability applications are available today and can be used in many severe mechanical, thermal and wear applications.
| Characteristics | Unit | 95 Al2O3 | 99 Al2O3 | ZrO2 | GPSi3N4 | 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 | 230 | 500 |
| Thermal Conductivity @R.T. | W/(m*k) | 18-25 | 30 | 2.2 | 25 | 20 | 1.7 |
| Thermal shock resistance | Δ(℃) | 220 | 180-200 | 280-350 | 450-650 | >1500 | 25-100 |
| Max. Working Temperature @R.T. | ℃ | 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. ) | - | 9.5 | 9.8 | 26 | 8.2 | 4.08 | 6.02 |
| Dielectric Strength | kV/mm | 16 | 22 | - | 16 | 375 | 40 |
About UniPreTec
UniPreTec provides high-performance ceramic products in Alumina, Zirconia, Boron Nitride, Machinable Glass Ceramic, Silicon Nitride and further special materials. Along with these materials, we offer several machining from which to choose such as cutting, drilling, sawing, turning, grinding, polishing etc.. Furthermore, our technologies and equipments allow us to provide various and flexible forming processes, like dry pressing, isostatic pressing, extrusion, injection moulding and slip casting.
