Niobium in superalloys

This metal is a significant addition to nickel superalloys, thanks to its extreme hardness, which is likened to that of titanium, but with a ductility similar to iron. Niobium is what is known as a refractory metal, alongside molybedenum, which is another commonly used element in superalloy composition. The other metals that fall into this category are tantalum, which we have already mentioned, tungsten and rhenium. All of these refractory metals have similar properties, including exceptional resistance to heat and wear. They all have a very high melting point and retain a high level of hardness at room temperature. All of which are very desirable properties in industrial nickel alloys.

While niobium is only used in very small quantities in nickel alloys, its addition lends superalloys a wide range of potential applications, and has done since it entered commercial use in the early 20th century. It is useful for gas pipelines, where its ability to withstand high temperatures without corroding or wearing is highly valued. The tiny amount used in each alloy is enough to give the overall alloy this superior strength. Niobium is also used widely in aerospace, for jet engines and in rocketry, thanks to its excellent stability at high temperatures.