Niobium and niobium alloy Overview and Applications

Niobium is a transition metal in Group 5 (VB) of the periodic table, is a chemical element with symbol Nb and atomic number 41. Niobium has a melting point of 2750 K (2477°C or 4491°F), and a boiling point of 5017 K (4744°C or 8571°F). It starts to oxidize in air at 200 C (392 F). When processed, it must be placed in a protective atmosphere at moderate temperatures. As a ductile transition metal, niobium has physical and chemical properties similar to those of the element tantalum. Niobium, a soft, shiny, white metal, is also known as columbium since it was originally discovered in a mineral named columbite. Like tantalum, niobium resists corrosion and maintains good physical properties at high temperatures but offers other outstanding attributes.

Niobium is used mostly in alloys, mainly in special steel such as those used in gas pipelines. Although these alloys contain a maximum of 0.1%, the small percentage of niobium enhances the strength of the steel. The temperature stability of niobium-containing superalloys is important for its use in jet and rocket engines. Niobium is used in various superconducting materials. These superconducting alloys, also containing titanium and tin, are widely used in the superconducting magnets of MRI scanners. Other applications of niobium include its use in welding, nuclear industries, electronics, optics, numismatics, and jewelry. In the last two applications, niobium's low toxicity and ability to be colored by anodization are particular advantages.

Niobium is used primarily in making alloys. For example, the addition of niobium to steel greatly increases its strength. One application of such steel is in the construction of nuclear reactors. Nuclear reactors are devices in which the energy of nuclear reactions is converted to electricity. Niobium steel is used because it keeps its strength at the very high temperatures produced there. Niobium alloys are also used in the construction of superconducting magnets. A superconducting material is one that has no resistance to an electric current. Once an electric current begins to flow in such a material, it continues to flow practically forever.

Products made from niobium by TNTI are employed in civil and military aerospace applications as a component in the superalloys in turbine blades, flame and heat shielding, and other parts of jet engines. In these applications, the outstanding properties of niobium under high temperature  contribute to structural integrity and fuel efficiency at high operating temperatures.

Niobium's resistance to high temperatures and chemical corrosion make it, and its alloys, common construction materials to construct processing equipment of chemical, pharmaceutical and nuclear plants. Niobium operates safely at high temperatures and chemical concentrations, while minimizing the contamination of products. Applications include: reaction vessels, liners and repair materials, instrumentation and safety devices such as thermowells, diaphragms, rupture discs and orifices.

As a starting material for electroceramics and metallic thin films for a long time, new niobium-based dielectric materials are showing promise in new capacitors and they are being sampled in the marketplace now. Niobium offers electronic properties similar to tantalum, but at a potentially lower cost.

Niobium offers high thermal conductivity, which is important to distillation equipment, heat exchangers, condensers, bayonet heaters, spiral coils, U-tubes, spargers, side-arm reboilers and thermowells. Thin-gauge niobium strips can be readily deep-drawn to produce inert laboratory crucibles and cups.