Zirconium Oxide (ZrO2)
Unlike other ceramic materials, zirconium oxide (ZrO2 –also known as zirconia) is a material with very high resistance to crack propagation. Zirconium oxide ceramics also have very high thermal expansion and are therefore often the material of choice for joining ceramic and steel.
Application Examples
Another outstanding property combination is the very low thermal conductivity and high strength. In addition, some types of zirconium oxide ceramics can conduct oxygen ions. Components made from this material are significantly more expensive than components made of alumina ceramics.
Zirconium oxide ceramics are used, among other applications, as tools for wire forming, as auxiliaries in welding processes, as materials for crowns and bridges in the dental industry, as insulating rings in thermal processes, and as oxygen measurement cells in lambda probes.
Properties of Zirconium Oxide (ZrO2)
- High thermal expansion (α=11 x 10-6/K, similar to some types of steel)
- Excellent thermal insulation/low thermal conductivity (2.5 to 3 W/mK)
- Very high resistance to crack propagation, high fracture toughness (6.5 to 8 MPam1/2)
- Ability to conduct oxygen ions (used for the measurement of oxygen partial pressures in lambda probes)