zirconiumoxide

Zirconium oxide, commonly called zirconia, is a white crystalline ceramic with the chemical formula ZrO2. It is the oxide of zirconium and is valued for high temperature stability, strength, and chemical inertness. Industrial zirconia is produced as a refined ceramic material and is used in a variety of applications due to its combination of hardness, toughness, and stability.

Zirconia exhibits three polymorphs by temperature: monoclinic at room temperature, transforming to tetragonal around 1170°C, and to cubic above about 2370°C. Pure zirconia is prone to cracking from these phase changes on cooling. Stabilizers such as yttria (Y2O3) or magnesia (MgO) are added to create stabilized zirconia (for example, yttria-stabilized zirconia, YSZ) that remains in tetragonal or cubic form at room temperature, enhancing toughness through transformation toughening.

Key properties include a high melting point about 2715°C, high hardness, and relatively high fracture toughness for stabilized grades. It has a density of roughly 5.68 g/cm³ and serves as a good electrical insulator. Zirconia is chemically inert in many environments and exhibits low reactivity with common acids and bases. Doped zirconia can be white and, with improved translucency, finds use in aesthetic applications alongside its durable mechanical performance.

Applications of stabilized zirconia are broad. In dentistry, it is used for crowns, bridges, and implant components due to its strength and tooth-like appearance. In engineering, yttria-stabilized zirconia serves as thermal barrier coatings for turbine blades and as electrolyte material in solid oxide fuel cells. It is also used for wear‑resistant components and precision ceramic parts produced by sintering and advanced manufacturing.

Safety considerations are generally straightforward: zirconia is largely non-toxic, but inhalation of fine powders should be avoided and standard industrial hygiene practices followed.