Zirconium atomic number is 40, with element symbol Zr. Zirconium element has an appearance of silvery metal, and the density is 6.52 g/cm3. Zr has a very small neutron adsorption cross-section and relatively high melting point (1855 °C or 3371 °F), making zirconium a great material for nuclear power rods. In 1990s, about 90% of zirconium produced every year is consumed by nuclear industry. However, as more and more people get familiar with Zr and its compound, more applications has been found.
Zirconium dioxide, or zirconia, is a very important zirconium compound. ZrO2 can be raw materials for technical ceramics, which has great hardness and wear resistance. Zirconia can be also in the form of transparent crystal and it is extremely hard, like diamonds. Thus, zirconium elements can be also found in Jewries, such as zirconium rings and zirconium crown, etc.
Zirconium metal and Zirconium alloys has advantage in specialized chemical environments - primarily acetic and hydrochloric acids. The corrosion resistance of Zirconium comes from a tightly adhered oxide that forms almost instantaneously. As a result, zirconium has been used to make electrodes components, flanges bolts, tubes and rods for special applications. Zirconium products also have wide applications in medical equipment, such as zirconium implants.
Zirconium based materials also been found to have some special properties. Zirconium has been used to make high temperature superconductive materials and Zr crystal bars are often used as the raw material. Zirconium alloys are also considered to be promising materials for commercial amorphous metal, also called metallic glass. Compared with common metal materials, amorphous metal has no grain boundaries, leading to better wear resistance and hardness. What is more, amorphous metals have no grain boundary corrosion and could be heat formed. To make the amorphous state, the melted alloys need to be cooled down fast. Usually the speed need to be millions K/s, the recently developed Zr based alloys could make it to be about 1K/s.
Zirconium demand is forecast to increase in the coming years due to demand of nuclear power plant worldwide. However, only few large companies occupy the technology need to make nuclear level zirconium materials, and the huge investment hinder entry of new players. Although, nuclear industry still consumes a large part of zirconium produced every year, applications in other fields, such as ceramics, have been developed quickly in recent decades.