Upon unloading and thermal cycling under
It is assumed that Miltefosine the retained texture in the Ni24.3Ti49.7Pd26 alloy was “pinned” by the lattice defects that were generated during thermomechanical cycling. Thus, the microstructure of the post-cycled (steps (i + ii + iii)) material was examined in the TEM and general examples are shown in Fig. 13 and Fig. 14. After cycling, the majority of the martensite still consisted of elongated parallel plates, but the nature of the martensite had changed from “self-accommodated” in the aged condition (Fig. 1c) to predominantly “reoriented” with only one set of 1 1 1 type I twins, as shown in Fig. 13a. The alternate plates labeled A, B and C in Fig. 13a show reoriented twin structure that is similar to that present in plates D and E, and also contain some detwinned areas with a complete loss of the originally present 1 1 1 type I twins. This suggests that the preferred martensite twin variant that was aligned closest to the loading direction was favored after loading and cycling. In addition, a high density of dislocations ( Fig. 13b and c) and some recovered regions bounded by subgrain boundaries (marked by arrows in Fig. 13b) were also observed in the microstructure. The interaction of dislocations with fine precipitates and anti-phase boundaries (arrows) is clearly seen in Figs. 13d and 14a. In addition, several new twinned structures were observed throughout the microstructure. These were more pronounced in the detwinned regions, as shown by arrows in Fig. 14c. Occasionally these were also observed in the plates containing an array of LIS 1 1 1 type I twins; an example of one such intersecting inclined set is shown by white arrows in Fig. 14b. Many of these twins appeared to originate from the martensite interplate boundaries where the dislocation density was somewhat higher. SADP of the circled area shown in Fig. 14c, suggested that these were 0 1 1 compound twins, which are not the LIS but considered deformation twins for the B19 to B2 transformation  and .