Features
Niobium is an off-white metal with a melting point of 2468°C and a boiling point of 4742°C. Niobium is stable in the air at room temperature and is not entirely oxidized when red-hot in oxygen. It can directly combine with sulfur, nitrogen, and carbon at high temperatures. It can form alloys with titanium, zirconium, hafnium, and tungsten. It does not interact with inorganic acids or alkalis, nor is it soluble in aqua regia but in hydrofluoric acid.

Application field
①Superconducting application: Niobium is one of the elements with the highest critical temperature for superconducting properties. The alloy made of niobium has a critical temperature as high as 18.50 to 210 absolute temperature and is currently the most crucial superconducting material;
②Superalloys: A large part of niobium in the world is used in the production of nickel, chromium, and iron-based superalloys in the form of pure metal or high-purity ferroniobium and niobium-nickel alloys. These alloys are used in jet engines, gas turbine engines, rocket components, turbochargers, and heat-resistant combustion equipment;
③Steel application: scrap niobium is the most effective microalloying element among various microalloying elements of steel. The role of niobium is so significant that the richness of niobium atoms in iron atoms can improve steel’s properties. Adding 0.001%-0.1% niobium to the steel is enough to change the mechanical properties of the steel;
④Coins: On coins, niobium is sometimes used together with gold and silver as precious metals on commemorative coins;
⑤Other niobium (or doped with 1% zirconium) is the sealing material of high-pressure sodium lamp arc tubes because the thermal expansion coefficient of niobium is very similar to that of sintered alumina arc lamp ceramic material.