In the present work we report some results concerning the evolutions of transformation temperatures and microstructure during thermal cycling in Ti- 47%Ni - 3% Co (atomic percent). In the case of bulk material (obtained by a conventional solidification method) high amounts of dislocations form during cycling, which produce a considerable evolution of the transformation temperatures (up to ~40K), while in meltspun material containing a dispersion of fine precipitates, the formation of dislocations during thermal cycling is highly reduced, giving rise to stable transformation temperatures. The dislocation characteristics have been analysed by means of two-beam condition observations as well as the Large Angle Convergent Beam Electron Diffraction technique. Some energetical considerations concerning the dislocations are pointed out to interpret the evolution of transformation temperatures
