Zirconia is the most important and potential material in this time. Now it is widely applied in almost all field of production. Zirconia is characterized by several properties which are useful for industrial applications, including high strength, high fracture toughness, excellent wear resistance, high hardness, excellent chemical resistance, high toughness, good oxygen conductivity and high refractories. Zirconia is a white crystalline oxide of zirconium. Its most naturally occurring form, with a monoclinic crystalline structure, is the rare mineral, baddeleyite. Pure ZrO2 has a monoclinic crystal structure at room temperature and transitions to tetragonal and cubic at increasing temperatures. The volume expansion caused by the cubic to tetragonal to monoclinic transformation induces very large stresses, and will cause pure ZrO2 to crack upon cooling from high temperatures. Several different oxides are added to zirconia to stabilize the tetragonal and/or cubic phases: magnesium oxide (MgO), yttrium oxide, (Y2O3), calcium oxide (CaO), and cerium oxide (Ce2O3), amongst others.
2.Application:
Unstabilized zirconia: suitable for ceramic pigments, ceramics capacitors, PZT ceramics, or producing other materials contained zirconia, etc. Partially stabilized zirconia: produced by adding stabilizing oxides, usually Y2O3, MgO, CaO or mixed oxides, Y2O3 stabilized zirconia permit excellent in structural ceramics, and others are suitable used in high temperature. Fully stabilized zirconia: construction of cubic crystal, widely used in refractories, gemstone, sensors, etc
