Zirconium oxide occurs as monoclinic, tetragonal and cubic crystal
forms. Densely sintered parts can be manufactured as cubic
and/or tetragonal crystal forms. In order to stabilise these crystal
structures, stabilisers such as magnesium oxide (MgO), calcium
oxide (CaO) or yttrium oxide (Y2O3) need to be added to the ZrO2.
Other stabilisers sometimes used are cerium oxide (CeO2),
scandium oxide (Sc2O3) or ytterbium oxide (Yb2O3).
Unlike other ceramic materials, 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.
high fracture toughness
thermal expansion similar to cast iron
extremely high bending strength and tensile strength
high resistance to wear and to corrosion
low thermal conductivity