Hot Working of High-Purity Nickel-Niobium Alloys
The present work deals with the influence of niobium in solid solution on the dynamic recrystallization of pure nickel. High-purity nickel and two model nickel-niobium alloys were deformed to large strains via torsion at temperatures between 800 and 1000°C. Niobium additions considerably increased the flow stress, while they lowered the strain-rate sensitivity and increased the apparent activation energy. EBSD of the steady-state microstructures revealed strong grain refinement. Substructure development was favored, whereas thermal twinning was reduced by niobium. More generally, discontinuous recrystallization kinetics were considerably decreased.
T. Chandra, K. Tsuzaki, M. Militzer , C. Ravindran
F. Montheillet et al., "Hot Working of High-Purity Nickel-Niobium Alloys", Materials Science Forum, Vols. 539-543, pp. 2966-2971, 2007