Tsirkooniumoksiid

Tsirkooniumoksiid, also known as zirconia, is a white crystalline oxide of zirconium with the chemical formula ZrO2. It is a highly refractory material, meaning it can withstand very high temperatures without deforming or melting. Zirconia is naturally found in the mineral baddeleyite, but it is most commonly produced synthetically from zircon sand.

The properties of zirconia are highly dependent on its crystalline structure, which can be cubic, tetragonal, or monoclinic. Pure zirconia typically exists in the monoclinic form at room temperature and transitions to tetragonal and then cubic at higher temperatures. However, these high-temperature phases are not stable at room temperature and tend to revert back to monoclinic, causing significant volume changes and cracking. To stabilize the tetragonal and cubic phases at room temperature, other metal oxides such as yttrium oxide (Y2O3) or calcium oxide (CaO) are added, creating stabilized zirconia.

Zirconia exhibits excellent mechanical strength, toughness, and wear resistance, along with good chemical inertness and biocompatibility. These properties make it suitable for a wide range of applications. In dentistry, yttria-stabilized zirconia is widely used for crowns, bridges, and implants due to its aesthetic appeal and durability. It is also employed in the aerospace industry for thermal barrier coatings on turbine blades, in the electronics industry as a dielectric material, and as a component in oxygen sensors. Furthermore, its high melting point and inertness make it a valuable material for crucibles and refractories used in high-temperature processes.