Niobium and Tantalum - Narayan Thakur | Scoop it! is shit! | Scoop.it
Niobium is an important microalloying element in steel. NIobium is used in nickel-, cobalt-, and iron-base superalloys which have been used in jet engines components, rocket sub-assemblies, and heat resisting and combustion equipments.

Tantalum is highly corrosive resistant and refractory metal like niobium and also finds use as a minor component in alloys. Being chemically inert to a great extent it is considered to be a substitute for platinum. Its main use is in capacitors..
Via Murry Shohat