Explanations of the charactaristics of Zirconium Oxide.
Zirconium Oxide is one of the most well known engineering ceramics and is referred to as Zirconia.
It is superior mechanical strength and fracture toughness than Alumina (Aluminum Oxide).
From normal temperature to elevated temperature, the pure zirconia crystal structure transforms from the monoclinic structure to the tetragonal structure and the cubic structure. So the volume also changes and as a result of thermal repetition its breakdown occurs. The pure zirconia is an instability material for temperature changes.
Therefore several oxides add to the zirconia to stabilize the material. The oxides are Yttrium oxide (Y2O3), Magnesium oxide (MgO), Calcium oxide (CaO), Cerium oxide (Ce2O3) etc. The crystal structure is cubic phase and it is referred to as Cubic stabilized zirconia or Stabilized zirconia.
And if the several oxides less than the above are added to pure zirconia, it has two crystal structures which are tetragonal structure and cubic structure. It is referred to as Partially stabilized zirconia. It has excellent fracture toughness.
And the stabilized zirconia is used in oxygen sensors and fuel cell membranes because it has the ability to allow oxygen ions to move freely through the crystal structure at high temperatures.
The other properties are extremely refractory, low thermal conductivity, chemical inertness, resistance to molten metals etc.
Fuel cell membranes. Oxygen sensors. Hot metal extrusion dies.
Marine pump seals and shaft guides.
Rollers and guides for metal tube forming.
etc.
