Glossary

Niobium (chemical symbol Nb) is a lustrous, gray transition metal known for its high strength, ductility, and excellent resistance to corrosion and high temperatures. It has an atomic number of 41 and lies directly above tantalum (Ta) in Group 5 of the periodic table, which explains why the two elements share very similar physical and chemical properties. In fact, niobium and tantalum often occur together in nature and must be carefully separated during processing.

Niobium has a melting point of about 2,468°C (4,474°F), making it one of the refractory metals—metals that can withstand extremely high temperatures without deforming. It forms a thin, stable oxide layer (Nb₂O₅) on its surface that gives it excellent resistance to oxidation and corrosion, even in harsh environments. This property, combined with its low thermal expansion and high melting point, makes it ideal for demanding structural and electronic applications.

One of niobium’s most important uses is as an alloying element in steels and superalloys. When added to stainless steel or high-strength low-alloy (HSLA) steels in small amounts (usually less than 0.1%), niobium refines grain structure and improves strength, toughness, and weldability. These niobium-bearing steels are widely used in pipelines, automotive frames, bridges, and skyscrapers. In superalloys, niobium increases high-temperature strength and creep resistance, making it essential for jet engine components, gas turbines, and rocket nozzles.

Niobium is also a key material in advanced technologies. In electronics, it’s used to produce niobium capacitors, which function similarly to tantalum capacitors but are less expensive. In the field of superconductivity, niobium-based alloys (like Nb-Ti and Nb₃Sn) are used to make superconducting magnets for MRI machines, particle accelerators, and fusion reactors, because niobium remains superconductive at relatively high magnetic fields and low temperatures.

The metal is naturally found in minerals such as columbite (also known as niobite) and pyrochlore, which are its primary commercial sources. Much of the world’s niobium supply comes from Brazil, which dominates global production, followed by Canada and a few other countries.