Properties and uses of zirconia

Zirconia scientific name is zirconium dioxide, molecular formula ZrO2, is the main oxide of zirconium, natural zirconium containing minerals mainly zirconium and zircon and so on. Zirconia is usually white odorless and tasteless crystals, difficult to dissolve in water, hydrochloric acid and dilute sulfuric acid, chemically stable, and has high hardness, high melting point, high resistivity, high refractive index and low thermal expansion coefficient characteristics, has been wear-resistant ceramics, refractories, machinery, electronics, optics, aerospace, biology, chemistry and other fields have been widely used, our common artificial drills and dental implants are also zirconia as the main material.

1. High hardness: the hardness of zirconia products can usually reach more than 7.5 on the Mohs scale, and the hardness of some products such as zirconia ceramics can exceed 9, second only to diamond. High hardness means that it has strong wear resistance, so zirconia ceramics are good anti-wear materials.

2. High melting point: zirconia has a melting point of up to 2715 °C, and has stable chemical properties, making it an excellent refractory material.

3. Low thermal conductivity and low expansion coefficient: The thermal conductivity of zirconia is low in common materials (1.6-2.03W/(m.k)), and the coefficient of thermal expansion is close to that of metals. Therefore, zirconia ceramics are suitable for making knotted ceramic materials, such as zirconia ceramic mobile phone appearance structural parts.

4. Special conductivity: zirconia is not conductive at room temperature, and the resistivity is extremely large, but in a high temperature environment, zirconia has a certain degree of conductivity, using this principle, zirconia is also used in many electronic devices