METHOD OF TEMPERATURE-DEFORMATION EFFECT ON TITANIUM-NICKEL ALLOYS WITH NICKEL CONTENT OF 49-51 at% WITH SHAPE MEMORY EFFECT Russian patent published in 2017 - IPC C22F1/18 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely, to heat treatment of alloys with shape memory, and can be used in medicine and engineering. Method of processing titanium-nickel alloys with the nickel content of 49–51 at% with the shape memory effect involves thermomechanical processing the billet, thermomechanical inducing the shape memory effect, unloading and heating for the shape recovery. Prior to thermomechanical processing the billet is subject to recrystallization annealing and tempering. Thermomechanical processing used is low-temperature thermomechanical treatment by multipass deformation at the temperature of 18–24 °C until the accumulated deformation degree is 42–60 %, then performed is deformation into the specified shape, its fixation and recrystallization annealing at the temperature of 550–650 °C for 30–70 minutes. Thermomechanical inducing the memory effect is performed by heating up to a temperature over A_k of reverse martensitic transformation, cooling down to the temperature of direct transformation start B2→R, deformation at that temperature by 21–25 % and holding at that temperature for 0.5–3 minutes, cooling down to the temperature of martensitic transformation end of -196 °C, holding at that temperature for 0.5–3 minutes.

EFFECT: implemented is the value of reversible deformation of 18,4 %.

1 cl, 2 dwg, 1 ex