This work presents a study of the development of the two-way shape memory effect (TWSME) by themomechanical training and its degradation due to working cycles in a shape memory alloys (SMAs) spring. A TWSME extension spring that could extend upon heating and contract upon cooling was obtained by constrained annealing and thermomechanical training. A stable TWSME recovery rate can reach 60-70% after training for 200 cycles. The investigation showed that constrained annealing temperature and the thermomechanical training procedure had a great effect on the TWSME. After 1000 working cycles, the TWSME recovery rate still maintained at 45% stably. The effect of the thermomechanical training on transformation characters was also investigated by differential scanning calorimetry (DSC). The inverse martensitic transformation temperatures increased and martensitic transformation temperatures decreased with increasing thermomechanical training cycles, which was attributed to the dislocations introduced into the TiNi shape memory alloys.

In this work, Ti-Ni shape memory alloy thin films were irradiated by 1.7MeV electron with three types of fluences: 4

In this work, Ti-49.8 at.% Ni shape memory alloy (SMA) thin films were irradiated by 60-keV protons with two types of doses: 5

Proton irradiation at temperatures of 310 and 350℃ has been explored as a method of studying radiation effects in Zircaloy 4 under power-reactor conditions. The dislocation-loop and hardness evolution are similar to those observed under neutron irradiation. Amorphization and Fe loss at Zr(Cr,Fe)2 precipitates are observed. Energy-filtered images indicate Fe accumulation in the matrix near the precipitate, a phenomenon not reported in neutron-irradiated alloys.

In this work, Ti-50.6 at.% Ni shape memory alloy were solution annealed at 800℃ for 20min and quenched in icy water, further annealing were done at 380℃ for 1h, and then irradiated with 1.7MeV electron at the fluence of 3.2×1020-12.8×1020m2. The evolution of transformation temperatures was studied by differential scanning calorimeter (DSC). Effect of annealing on the evolution of multiple-step transformation temperatures also investigated. Heat treatment and irradiation had a prominent effect on the transformation, but with different characteristics. The M1 (the first R-phasefimartensite transformation) showed little change after irradiation, but the M2 (the second R-phasefimartensite transformation) transformation temperature decreased with increasing electron fluence and disappeared at the fluence of 12.8×1020m2. Heat treatment causes the shift of R-phase transformation start/finish temperature (Rs=Rf ) to lower temperature and the shift of M1 and M2 transformation temperatures to higher temperature. The peaks of M1 and M2 almost merged into one peak with increasing annealing temperature. The effects of irradiation and annealing on the transformation characteristics are not exchangeable, so irradiation is also an important method for the study of condensed matter.