In contrast to other ceramic materials, zirconium oxide (ZrO2) has a very high resistance to the propagation of cracks. In addition, zirconium oxide ceramic has a very high thermal expansion and is therefore a popular choice when creating connections between ceramic and steel.
High thermal expansion (y = 11 x 10 -6 / K, similar to some types of steel) Very good thermal insulation or low thermal conductivity (2.5 to 3 W / mK) Very high resistance to the propagation of cracks, high crack toughness (6.5 to 8 MPam 1/2) Ability to conduct oxygen ions (used when measuring oxygen partial pressures in lambda probes)
Another outstanding combination of properties is the very low thermal conductivity combined with high strength.
In addition, some types of zirconium oxide ceramic have an oxygen ion conductivity. In terms of costs, components made from this material are significantly higher than those made from aluminum oxide ceramic.
Zirconium oxide ceramics are used, for example, as tools for wire forming, as an aid in welding processes, as a material for crowns and bridges in the dental industry, as an insulating ring in thermal processes and as an oxygen measuring cell in the lambda probe.