Niobium alloy


A niobium alloy is one in which the most common element is niobium.

Alloys used for the production of other alloys

The most common commercial niobium alloys are ferroniobium and nickel-niobium, produced by thermite reduction of appropriate mixtures of the oxides; these are not usable as engineering materials, but are used as convenient sources of niobium for specialist steels and nickel-based superalloys. Going via an iron-niobium or nickel-niobium alloy avoids problems associated with the high melting point of niobium.

Superconducting alloys

and Niobium-titanium are essential alloys for the industrial use of superconductors, since they remain superconducting in high magnetic fields ; there are 1200 tons of NbTi in the magnets of the Large Hadron Collider, whilst Nb3Sn is used in the windings of almost all hospital MRI machines.

Aerospace rivets

Niobium-titanium alloy, of the same composition as the superconducting one, is used for rivets in the aerospace industry; it is easier to form than CP titanium, and stronger at elevated temperatures.

Refractory alloys

Niobium-1% zirconium is used in rocketry and in the nuclear industry. It is regarded as a low-strength alloy.
C-103, which is 89% Nb, 10% Hf and 1% Ti, was used for the rocket nozzle of the Apollo service module; it is regarded as a medium-strength alloy.
High-strength alloys include C-129Y, Cb-752, and the even higher strength C-3009 ; these can be used at temperatures up to 1650°C with acceptable strength, though are expensive and hard to form.
Niobium alloys in general are inconvenient to weld: both sides of the weld must be protected with a stream of inert gas, because hot niobium will react with oxygen and nitrogen in the air. It is also necessary to take care to avoid copper contamination.