Zirconia (ZrO2) has a melting point of 2715°C and a Mohs hardness of 7. Because of its high chemical inertness and high melting point, it is an excellent refractory material that can be used for sintering backing materials to prevent the adhesion of porcelain.
Zirconia ceramics is a very important structural ceramic second only to alumina ceramic. Zirconia has a high hardness, high strength and toughness, low specific heat capacity, and thermal conductivity. It is widely used in structural ceramics and functional ceramics, such as cutting tools, mechanical parts, advanced refractory materials, high-temperature anion conductors, oxygen sensors, etc.
The disadvantage of zirconia is that its strength and toughness will be seriously attenuated at high temperatures, which limits its application under high-temperature conditions.
Zirconia Parameters
| Composite | (wt %) | 96.5% |
| Color | White | |
| Density | g/cm3 | 6.02 |
| Hardness | HRA | 13 |
| Flexural Strength | Mpa(psi*103 ) | 1000 |
| Gas Permeability | 0 | |
| Water Absorption | % | 0 |
| Thermal Shock Resistance | °C | 350 |
| Thermal Expansion | ×10-6/℃ | 10 |
| Dielectric Constant,20°C | 1MHz | – |
| Dielectric loss, tanδ | 1MHz | 2×1014 |
| Volume Resistivity,20℃ | Ω·cm | ≥1015 |
| Dielectric Strength,DC | Ω·cm | ＞10 |
| Compressive Strength | KV/mm | 3100 |
| Fracture Toughness | MPa( psi * 103) | 9-10 |
| Poisson’s Ratio | MPa | 0.3 |
| Thermal conductivity | W/mK | 3 |
