As a result of low-temperature aging at 573 K for 1.5 h of Ti–50.6 at% Ni [001]-oriented single crystals quenched from 1253 K, a high-strength state is obtained due to the precipitation of Ti_3Ni_4 nanoscale particles ( d < 10 nm). The aging leads to the development of the B 2– B 19' martensitic transformation through an intermediate R phase, a reduction in the B 19' martensite formation temperatures by 40–60 K, an increase in the strength properties of the B 2 phase from 730 to 2100 MPa, and an extension of the superelasticity interval Δ T _SE in compression from Δ T _SE = 60 to 170 K (compared to quenched crystals).