Influence of niobium solutes on the mechanical behavior of nickel during hot working

An experimental program was performed to determine the rheology and influence of niobium additions to high-purity nickel on dynamic-recrystallization behavior during hot working. Various high-purity alloys were prepared (pure Ni and Ni-0.01, 0.1, 1, 2, 5 and 10 wt% Nb) and deformed to high strains by hot torsion to characterize the mechanical behavior within the temperature range from 800 to 1000 °C at (von Mises equivalent) strain rates of 0.03, 0.1 and 0.3 s−1. A simple analytical method was proposed for predicting the strain-hardening and dynamic-recovery parameters in the classical Yoshie-Laasraoui-Jonas equation. By the means, the effect of niobium solutes on plastic flow was determined, thus enabling a reasonable fit for the flow curves for the entire range of solid solution Ni-Nb alloys.