ULTRA-FINE GRAIN TWO-PHASE ALPHA-BETA TITANIUM ALLOY WITH IMPROVED LEVEL OF MECHANICAL PROPERTIES, AND METHOD FOR ITS OBTAINMENT Russian patent published in 2013 - IPC C22F1/18 C22C14/00 B82B3/00 

FIELD: metallurgy.

SUBSTANCE: invention refers to nanostructured materials with ultra-fine grain structure, and namely two-phase alpha-beta titanium alloys which can be used for manufacture of semi-finished products and products in different branches of engineering, machine-building industry and medicine. Proposed alloy has microstructure consisting of ultra-fine grains of alpha-phase and beta-phase with the size of less than 0.5 mcm. In alloy microstructure the amount of grains with grain shape coefficient of not more than 2 is not less than 90%; at that, more than 40% of grains have wide-angle borders, and average density of dislocation is not more than 10¹⁴ m^-2. the method for obtaining ultra-fine grain two-phase alpha-beta titanium alloy involves heat treatment with heating of a billet at the temperature of not more than 0.6 T_"пп", further multicycle intense plastic deformation with achievement of accumulated true deformation degree e≥4. Then, plastic deformation is performed so that the billet shape is changed at the rate of less than 10^-1 s^-1 in several cycles to provide deformation degree ε≥50%.

EFFECT: improving strength and fatigue properties and preserving high ductility.

5 cl, 2 dwg, 1 tbl, 1 ex