METHOD OF PRODUCING WORKPIECES OF TiHfNi ALLOYS Russian patent published in 2019 - IPC B22F3/16 B22F9/18 C22C14/00 C22C19/03 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to production of compact deformable workpieces from TiHfNi alloys with high-temperature shape memory effect. Method includes hydride-calcium synthesis of powder mixture at temperature of 1,100–1,300 °C for at least 6 hours, after which the obtained products are treated with water, and then with a solution of hydrochloric acid, then obtained powder is consolidated by pressing with formation of pressing of required shape, which is subjected to sintering in vacuum at residual pressure of not more than 10^-4 mm Hg at temperature of not less than 0.95 of alloy melting point for not less than 2 hours. Powder mixture is prepared from TiO₂, HfO₂, Ni or Ni+NiO and calcium hydride. In the finished alloy nickel concentration is set at level of 50.0–50.5 at%, hafnium at level of 10.0–20.0 at%, titanium – the rest.

EFFECT: homogeneity of the phase composition represented by the martensitic phase B19, which ensures deformability of the workpiece, as well as recurrence of direct and reverse martensitic transformations in all temperature alloys.

1 cl, 10 tbl, 3 ex