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Niobium oxidizes in Earth's atmosphere very slowly, hence its application in jewelry as a hypoallergenic alternative to nickel. Niobium is often found in the minerals pyrochlore and columbite. Its name comes from Greek mythology: Niobe, daughter of Tantalus, the namesake of tantalum. The name reflects the great similarity between the two ...
Small amounts of niobium are added to stainless steel to improve its quality. Niobium alloys are also used in rocket nozzles because of niobium's high corrosion resistance. [19] Tantalum has four main types of applications.
Columbite, also called niobite, niobite-tantalite and columbate, with a general chemical formula of (Fe II,Mn II)Nb 2 O 6, is a black mineral group that is an ore of niobium. It has a submetallic luster, a high density, and is a niobate of iron and manganese. Niobite has many applications in areospace, construction and the medical industry.
The definition of which elements belong to this group differs. The most common definition includes five elements: two of the fifth period (niobium and molybdenum) and three of the sixth period (tantalum, tungsten, and rhenium). They all share some properties, including a melting point above 2000 °C and high hardness at room temperature. They ...
Niobium carbide (Nb C and Nb 2 C) is an extremely hard refractory ceramic material, commercially used in tool bits for cutting tools. It is usually processed by sintering and is a frequent additive as grain growth inhibitor in cemented carbides. It has the appearance of a brown-gray metallic powder with purple lustre. It is highly corrosion ...
Even if the material's resistivity is known, calculating the resistance of something made from it may, in some cases, be much more complicated than the formula = / above. One example is spreading resistance profiling , where the material is inhomogeneous (different resistivity in different places), and the exact paths of current flow are not ...
Niobium-1% zirconium is used in rocketry and in the nuclear industry. It is regarded as a low-strength alloy. [1] [2]C-103, which is 89% Nb, 10% Hf and 1% Ti, is used for the rocket nozzle of the Apollo service module and the Merlin vacuum [3] engines; it is regarded as a medium-strength alloy.
For example, superconducting Niobium–titanium wires have an RRR defined as () / (). [ 1 ] In the Kondo effect the resistivity begins to increase again with cooling at very low temperatures, and the value of RRR is useful for characterizing this state.