METHOD OF DEFORMATION TREATMENT OF LONG-DIMENSIONAL SEMI-FINISHED PRODUCTS OF THIN SECTION FROM TINI ALLOYS WITH SHAPE MEMORY EFFECT Russian patent published in 2019 - IPC C22F1/18 C22F3/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to electroplastic forming of titanium-nickel alloys to increase their deformability and shape memory effect and can be used in metallurgy and mechanical engineering. Method of deformation processing of long semi-finished products of thin section of Ti_50-xNi_50+x alloys with shape memory effect includes multi-pass rolling of pre-hardened semi-finished product in austenitic state at deformation temperature T_d > M_d for Ti_50-xNi_50+x alloys at x > 0.3 and in martensitic state at temperature M_e < T_d < M_b for Ti_50-xNi_50+x alloys at x = 0–0.3 and until the e > 0.3 total true degree of deformation is reached, where T_d – deformation temperature, M_b and M_e – temperature of the beginning and end of the direct transformation, M_d – temperature of existence of stable austenite. Produce a simultaneous impact of a pulsed electric current with density of 5–1000 A/mm², frequency of 100–1000 Hz and duration of 10–1000 mcs. Get the semi-finished products of thin section of Ti_50-xNi_50+x alloys with a shape memory effect and with a uniform ultrafine-grained structure with a grain size of 50 < d < 500 nm, which have a high deformation capacity of e > 1 and high crack resistance.

EFFECT: method allows to control the structure parameters and provide a complex of high technological and functional properties.

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