Niobium has a number of uses: it is a component of some stainless steels and an alloy of other nonferrous metals. These alloys are strong and are often used in pipeline construction. Other uses;
The metal has a low capture cross-section for thermal neutrons and so finds use in the nuclear industries.
It is also the metal used in arc welding rods for some stabilized grades of stainless steel.
Appreciable amounts of niobium in the form of high-purity ferroniobium and nickel niobium are used in nickel-, cobalt-, and iron-base superalloys for such applications as jet engine components, rocket subassemblies, and heat-resisting and combustion equipment. For example, advanced air frame systems such as those used in the Gemini program used this metal.
Niobium is being evaluated as an alternative to tantalum in capacitors.
Because niobium metal and some niobium alloys are physiologically inert (and thus hypoallergenic), they are used in jewelry and in medical devices such as pacemakers. Niobium metal treated with sodium hydroxide forms a porous layer that aids osseointegration.
Along with titanium, tantalum, and aluminum, Niobium can also be electrically heated and anodized to a wide array of colors using a process known as reactive metal anodizing. This makes it very attractive for use in jewelry.
Niobium is also added to glass in order to attain a higher refractive index, a property used in the optical industry to make thinner corrective glasses.
In 2005, the country of Sierra Leone made a coin honoring Pope John Paul II that contained a disc of 24-carat gold surrounded by a ring of purple-tinted Niobium.
Niobium becomes a superconductor when lowered to cryogenic temperatures. At atmospheric pressure, it has the highest critical temperature of the elemental superconductors: 9.3 K. Niobium has the largest magnetic penetration depth of any element. In addition, it is one of the three elemental superconductors that are
Type II (the others being vanadium and technetium), meaning it remains a superconductor when subjected to high magnetic fields. Niobium-tin and niobium-titanium alloys are used as wires for superconducting magnets capable of producing exceedingly strong magnetic fields. Niobium is also used in its pure form to make superconducting accelerating structures for particle accelerators.