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The method of grain refinement is described which is used to obtain titanium and zirconium base alloys in an ultra-fine grain state. The method involves abc-press forging and subsequent multiple-pass die rolling. It is shown that annealing performed at temperatures below the recrystallization threshold would cause formation of a stable nanostructure. The characteristics of such nanostructure would remain unaffected even at high plastic deformation levels until the fracture of the object made from this material. Both alloys having nanostructure are suitable for medical applications.

The results of studies on the deformation behavior during quasistatic tension of zirconium-based alloy samples (Zr-1 wt.% Nb) in microcrystalline and ultrafine-grained states are presented. The patterns of strain field distributions on the surface of the samples under tension have been obtained using a three-dimensional digital optical system Vic-3D. It has been established that the deformation difference in the plastic strain zone relative to the deformation, averaged over the entire sample, depends on the structural state of the Zr-1Nb alloy at the stage preceding destruction of the samples. Based on the analysis of the distribution patterns of strain fields, the Poisson’s ratio and the Gruneisen parameter in the plastic strain zone have been determined.

Fatigue testing of ultrafine-grained, fine-grained and coarse-grained VT1-0 and Zr–1 wt. % Nb samples was performed under conditions of gigacycle fatigue regime. It was established that ultrafine-grained titanium and zirconium alloy samples initiate increasing fatigue strength of up to 1.3 times for titanium and 1.7 times for zirconium alloy within gigacycle region (109 cycles) comparable to fine-grained and coarse-grained samples. Analysis of fracture surface morphology has revealed the similar fractured structure in coarse-grained and ultrafine-grained titanium and zirconium alloy samples. Fractures in ultrafine-grained titanium and zirconium alloy samples exhibit quasi-brittle pattern.