Shape memory effect at cabling nitrated titanium nickelide

The diffusion band of the nitrated TiNi is subdivided into three subbands and characterized by the lack of the clearly expressed boundaries between them and by a smooth variation of the phase composition. Facing (subband- 1) of the nitrated samples consists of δ-TiN only after nitriding for 0.5 hour. Subband-2 is a hard alloy based nitrides δ-TiN and Ti₄Ni₂N with the bunch of B2-phase TiNi (cubic high temperature modification). The quantity of δ-TiN decreases up to zero and inclusion volume fraction Ti₄Ni₂N rises up to the maximum values near the low boundary of the subband-2. In subband-3 the phase composition changes in the following order: Ti₄Ni₂N+B2-TiNi→B2-TiNi→B2-TiNi+B19´-TiNi. In central bands of the nitrated samples the initial structure of martensite B 19´ is retained. The content of Ni in B2-TiNi changes fluently from the maximum value near the upper boundary of the subband-2 up to approximately equiatomic composition near the low boundary of the diffusion band. In cooling lower-than 300 K B2-TiNi of the diffusion band composition tests martensite transformations (MT) into rhombohedral R or monoclinic B 19´ martensite phases.