Diffusional decomposition of a strongly deformed Nb-Ti alloy

The effect of severe plastic deformation on the decomposition of supersaturated solid solution has been investigated. A study has been performed on a metastable niobium-titanium alloy (NT-50). It has been established that an increase in the true plastic prestrain of the NT-50 alloy from 4 to 7.6 leads to the significant acceleration of supersaturated solid solution decomposition at all treatment times (from 50 to 2000 h). The volume fraction of the precipitated α-Ti phase increases by ∼(40–50)%. The true prestrain growth brings changes in the mechanisms responsible for the increase in the fracture of the precipitated phase. At the increased true prestrains, the volume fraction of the phase increases with growing sizes of precipitates at a constant and even slight decrease in their density, while at smaller true prestrains, the growth occurs at the expense of the increased number density of the precipitated particles with approximately the same sizes.