What is zirconium used for?
Zirconium has an atomic number of 40 and an element symbol of Zr. The element zirconium appears as a silvery metal with a density of 6.52 g/cm3. Zr has a very small neutron adsorption cross section and a relatively high melting point (1855°C or 3371°F), making it an excellent material for nuclear power rods. In the 1990s, about 90% of the zirconium produced each year was consumed by the nuclear industry. However, as more people became familiar with Zr and its compounds, more applications were found.
Zirconium dioxide, or zirconium oxide, is a very important zirconium compound. ZrO2 can be used as a raw material for technical ceramics with high hardness and wear resistance. Zirconium oxide can also be in the form of transparent crystals, which are very hard, just like diamonds. Therefore, the element zirconium also appears in jewelry, such as zirconium rings, zirconium crowns, etc.
Zirconium metal and zirconium alloys have advantages in special chemical environments - mainly acetic acid and hydrochloric acid. Zirconium's corrosion resistance comes from a tightly adherent oxide that forms almost instantly. Therefore, zirconium has been used to make electrode assemblies, flange bolts, tubes and rods for special purposes. Zirconium products are also widely used in medical devices, such as zirconium implants.
Zirconium-based materials have also been found to have some special properties. Zirconium has been used to make high-temperature superconducting materials, and zirconium crystal rods are often used as raw materials. Zirconium alloys are also considered promising materials for commercial amorphous metals (also known as metallic glasses). Compared with ordinary metal materials, amorphous metals have no grain boundaries and therefore have better wear resistance and hardness. In addition, amorphous metals have no grain boundary corrosion and can be hot-formed. In order to form an amorphous state, the molten alloy needs to be cooled quickly. Usually, the cooling rate needs to reach millions of K/s, and the recently developed Zr-based alloys can make it reach about 1K/s.
Due to the global demand for nuclear power plants, the demand for zirconium is expected to increase in the next few years. However, only a few large companies have the technology required to manufacture nuclear-grade zirconium materials, and huge investments have hindered the entry of new players. Although the nuclear industry still consumes a large amount of zirconium every year, the application of zirconium in other fields such as ceramics has developed rapidly in recent decades.
