Niobium, discovered in 1801 by English chemist Charles Hatchett, is a unique chemical element with the symbol Nb and atomic number 41. Shiny and whitish-silver, this special metal has a number of remarkable properties which make it ideal for specialist applications. When very pure, it is soft and ductile, although when blended with other materials it becomes harder, and it has an extremely high melting point, only becoming liquid at a staggeringly high 2750°C.
Named after America, where it was discovered – Columbia being the poetic name for the United States – the element was originally named Columbium, and was often confused with Tantalum. Finally resolving this confusion, German chemist Heinrich Rose reidentified the element and differentiated it at last from Tantalum, recognising that it was closely related and naming it Niobium after Niobe, the daughter of Tantalus in Greek Mythology.
The Uses of Niobium
Niobium is used across a huge variety of industries, both in its pure form and in alloys and compounds which make use of its outstanding physical and chemical properties to create materials that would not otherwise be possible.
Why is Niobium Added to Steel?
Niobium is added to steel as a microalloying element, added in small quantities to create niobium carbide and niobium nitride, which provide multiple advantages to the steel. The addition of small amounts of niobium to steel improves grain refining, slows recrystallisation and reduces the rate of precipitation hardening. Niobium is a very important component of high strength low alloy steels, added in small proportions to greatly improve the strength of the steel and raise its melting point. This steel is an important component in automobile frames and other vehicle construction.
When added in larger quantities, niobium steels become much harder and more resistant to wear and damaging forces, commonly seen in particularly hardy machine components, wear-resistant blades, and pipelines. These high-niobium steels are strong enough and durable enough to be perfect for use in intercontinental pipelines, which is one of the most prominent uses for them.
Why is Niobium Used in Jewellery?
Niobium is used in jewellery thanks to its hypoallergenic nature, shiny, lustrous appearance, easy workability and the beautiful range of colours that it can display when anodised.
Niobium jewellery commonly has an anodised surface, causing diffraction of light and displaying a range of colours. Lustrous blues, greens, browns, purples, violets, yellows, whites and silvers can all be created using this process, and in some cases, special anodised or oxidised finishes can be created which are completely unique, making sure no two items of jewellery are exactly alike.
Niobium in its pure form, alongside some niobium alloys, is completely physiologically inert and hypoallergenic, meaning that it won’t cause any reaction from the body. This naturally suits niobium for use in implants and pacemakers, as it won’t face rejection or cause irritation in a recipient, and can even be treated to encourage osseointegration in implants, helping bone to fuse with the implant and more completely heal.
Is Niobium Used as a Superconductor?
Niobium is a popular superconductor, especially when alloyed with titanium or germanium.
Niobium wire is the primary superconductor used in the Large Hadron Collider, with more than 600 tonnes of niobium-tin wire and 250 tonnes of niobium-titanium wire used across the machine in the form of superconducting magnets.
Outside of cutting-edge international scientific facilities, niobium is used in superconductors and superconducting magnets in Magnetic Resonance Imaging equipment and other medical scanning equipment, providing vital diagnostic capacity to hospitals across the world. Every year, billions of pounds of clinical magnetic resonance imaging systems are built using niobium-based superconducting wire in their superconducting magnets, and they are used in a huge range of medical fields, from oncology and cancer treatment to emergency trauma medicine and neurology.
Why is Niobium Used in Superalloys?
As well as being a superconductor, niobium is used in one other “super” application – superalloys, formed from precise quantities of many different metals for extreme performance in extreme applications – applications such as jet engine turbines, space rockets, turbo charger systems and combustion equipment, among other high-intensity situations.
Often used in nickel-, cobalt- or iron-based superalloys, niobium provides hardness, resistance to thermal creep and improved melting point (as pure niobium remains solid up to a temperature of 2750°C). The addition of niobium to superalloys also precipitates a hardening phase within the superalloy’s grain structure, improving it immensely and providing a considerable boost to the superalloy’s performance across the board.
What are the Other Uses for Niobium?
In addition to the specialist uses listed above, niobium is used in a range of other capacities, including in unique coins, arc welding and electroceramics, which make use of its inimitable properties to provide a range of results.
Niobium in Coin-Making
Niobium is a commonly-used metal in commemorative coin-making, often in combination with silver or gold. When used in coin-making, niobium is usually selectively anodised, creating a very thin layer on the surface which, by diffraction of light, causes colours to appear on the surface. A huge range of colours are available, and thanks to the corrosion resistance of niobium, especially in partnership with silver and gold, these coins are able to survive in collections or museums indefinitely.
Niobium in Arc Welding
Thanks to its extremely high melting point of 2750°C, niobium is a critical component of arc welding rods for some stainless steels. At arc welding temperatures, most metals will be completely melted or even vaporised, so an element capable of handling such extreme conditions is needed. Niobium fits the bill perfectly.
Niobium is a key ingredient in the production of lithium niobate, which is used very extensively in the telecoms market, in the construction of mobile phones, optical modulators and other high-tech communications and computing equipment. Niobium is also added to glass to create a new glass form with a higher refractive index, making it possible to create thinner, finer lenses, reducing weight and improving quality in cameras, optical equipment and eyeglasses.
Contact Special Metals today!
If you would like to know more about the uses for niobium, and the niobium products available from Special Metals UK, you can get in touch with us on 01268 820409 or use the contact form on this page to get in contact!
The metals experts at the Special Metals head office have been leading the UK metals industry for decades, and will be happy to answer any questions you may have, provide industry advice and guidance, and process orders, making sure that you get the materials that you need at unbeatable quality and price!
No matter what the uses for niobium you are planning, you can rely on Special Metals to provide!