Fabrication of niobium and niobium alloys

Niobium, niobium-tantalum, niobium-vanadium and niobium-titanium metal and alloys are readily fabricated using standard techniques for deformation. The primary design considerations are the metallurgical structure, grain size, uniformity, and for niobium-titanium alloys the alpha-beta phase transformation. For the alloys designed for improved strength at elevated temperatures, an associated reduction of ductility requires the use of high temperatures and compressive modes of deformation to refine the cast structure. Fracture sensitivity decreases (i.e., toughness improves) after the cast structure is worked and refined to provide greater grain boundary area which is lower in impurity phase decoration then the cast structure. The material cost for niobium and the alloys is high, so that the success of the metallurgist in applying sound manufacturing techniques is important. each operation, niobium and the alloys can be successfully processed. (AU)