Zirkoniumoksidia

Zirkoniumoksidia, also known as zirconium oxide, is a white crystalline oxide of zirconium with the formula ZrO2. It occurs in nature as the mineral baddeleyite and is produced commercially for ceramics, engineering, and medical uses. The compound is highly refractory, with a melting point around 2680–2715 °C, and it exhibits high hardness and mechanical strength.

Pure ZrO2 exists in several crystalline forms: monoclinic at room temperature, tetragonal at intermediate temperatures, and cubic at high temperatures. These phase transitions involve volume changes that can make pure zirconia relatively brittle. Stabilizers such as yttrium oxide (Y2O3) or cerium oxide are added to obtain stabilized zirconia, which remains tetragonal or cubic at room temperature. This stabilization enables transformation toughening, increasing fracture resistance.

Applications include dentistry, where yttria-stabilized zirconia crowns, bridges, and implants are valued for aesthetics and strength. In ceramics and engineering, zirconia is used for tough ceramic parts and cutting tools. In energy and coatings, stabilized zirconia serves as an electrolyte in solid oxide fuel cells and as a thermal barrier coating in turbine engines.

Production involves processing zircon (ZrSiO4) ores to extract zirconium compounds, followed by conversion to ZrO2 and stabilization as needed. Safety: zirconia is generally non-toxic and biocompatible; inhaling fine powders may irritate the respiratory tract, so standard handling precautions apply.