The transformation behavior of a TiNiCu shape memory alloy electrolyticallycharged with hydrogen was investigated by means of different scanning calorimetry (DSC), opticalmicroscope and X-ray diffraction (XRD). The re...The transformation behavior of a TiNiCu shape memory alloy electrolyticallycharged with hydrogen was investigated by means of different scanning calorimetry (DSC), opticalmicroscope and X-ray diffraction (XRD). The results showed that inter- and inner-granular hydridesformed after charging with hydrogen, and the hydrides suppressed martensitic transformation. Theelectrolytically charged hydrogen can be easily released by heat treatment and the transformationoccurred again, which was verified by the DSC and XRD experiments.展开更多
Two-way shape memory effect (TWSME) was induced into the TiNi shape memoryalloys (SMAs) spring by thermomechanical training after annealing treatment, which has promisingapplication in micro-actuating fields. The TWSM...Two-way shape memory effect (TWSME) was induced into the TiNi shape memoryalloys (SMAs) spring by thermomechanical training after annealing treatment, which has promisingapplication in micro-actuating fields. The TWSME spring can contract upon heating and extend uponcooling. The results show that there is an increase of the recovery ratio up to a maximum TWSME of45%. During the training procedure, transformation temperatures and hysteresis were measured bydifferent scanning calorimetry (DSC). The results show that A_s (reverse transformation starttemperature) and A_f (reverse transformation finish temperature) shift to lower temperature aftertraining. The intervals of A_fA_s and M_s-M_f (M_s and M_f are the martensite start and finishtemperatures, respectively) increase and the heat of transformation decreases after training. Theelectrothermal driving characteristics of the TWSME springs were also investigated with alternatingcurrent density of 3.2-14.7 A/mm^2. It is found that the time response and the maximum contractionratio greatly depend on the magnitude of the electrical current density.展开更多
基金This project is financially supported by the National Natural Science Foundation of China (No.10175042) and by the Pro-gram for New Century Excellent Talents in Universities.
文摘The transformation behavior of a TiNiCu shape memory alloy electrolyticallycharged with hydrogen was investigated by means of different scanning calorimetry (DSC), opticalmicroscope and X-ray diffraction (XRD). The results showed that inter- and inner-granular hydridesformed after charging with hydrogen, and the hydrides suppressed martensitic transformation. Theelectrolytically charged hydrogen can be easily released by heat treatment and the transformationoccurred again, which was verified by the DSC and XRD experiments.
基金This project is financially supported by the National Natural Science Foundation of China (No. 10175042)
文摘Two-way shape memory effect (TWSME) was induced into the TiNi shape memoryalloys (SMAs) spring by thermomechanical training after annealing treatment, which has promisingapplication in micro-actuating fields. The TWSME spring can contract upon heating and extend uponcooling. The results show that there is an increase of the recovery ratio up to a maximum TWSME of45%. During the training procedure, transformation temperatures and hysteresis were measured bydifferent scanning calorimetry (DSC). The results show that A_s (reverse transformation starttemperature) and A_f (reverse transformation finish temperature) shift to lower temperature aftertraining. The intervals of A_fA_s and M_s-M_f (M_s and M_f are the martensite start and finishtemperatures, respectively) increase and the heat of transformation decreases after training. Theelectrothermal driving characteristics of the TWSME springs were also investigated with alternatingcurrent density of 3.2-14.7 A/mm^2. It is found that the time response and the maximum contractionratio greatly depend on the magnitude of the electrical current density.
