Substructural-Phase Transformations during Heat Treatments of the Ti–50.9 at % Ni Nanocrystalline Alloy

Abstract

The method of transmission electron microscopy is used to study the grain-subgrain structure of the Ti–50.9 at % Ni nanocrystalline alloy after heat treatments at 300–500°C. It is found that the decomposition of the B₂ solid solution of TiNi by the heterogeneous mechanism occurs in the subgrain structure, while the Ti₃Ni₄ particles are not observed in nanograins. The features of the recovery and recrystallization of the alloy and their relationship with the processes of dissolution and precipitation of Ti₃Ni₄ particles are revealed.