Niobium is used in alloys including stainless steel: A method for the production of niobium containing steel (1949). It improves the strength of the alloys, particularly at low temperatures: Niobium-Containing Ferritic Stainless Steel Excellent In Low Temperature Toughness Of Hot Rolled Sheet (1998).
Alloys containing niobium are used in jet engines (Titanium-aluminium-niobium alloy – used for jet engine compressor blades (1973)), and rockets (Copper-Niobium, Copper-Vanadium, Or Copper-Chromium Nanocomposites, And The Use Thereof In Heat Exchangers (2011)).
This element also has superconducting properties. It is used in superconducting magnets for particle accelerators (Magnet Structure For Particle Acceleration (2007)), and MRI scanners (Niobium 47 Weight % Titanium By Iron Addition And Method For Making Superconducting Multifilamentary Wire (1996)).
Niobium oxide and other metal oxides are added to glass (Pyrogenic Niobium Oxide – Useful For Prodn. Of Catalysts, Ceramics And Glass (1992)) to make high performance optical components (Optical glass, useful for producing optical elements such as lenses and prisms, comprises silicon dioxide, diboron trioxide, aluminum trioxide, lanthanum oxide, niobium oxide, calcium oxide, zinc oxide, titanium dioxide and zirconium oxide (2010)).
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All patent information has been obtained from Espacenet (European Patent Office).