Two-way shape memory effect and alternating current driving characteristics of a TiNi alloy spring  

作　　者：WANGZhiguo ZUXiaotao 

机构地区：[1]DepartmentofAppliedPhysics,UniversityofElectronicScienceandTechnologyofChina,Chengdu610054,China

出　　处：《Rare Metals》2004年第3期250-254,共5页稀有金属（英文版）

基　　金：This project is financially supported by the National Natural Science Foundation of China (No. 10175042)

摘　　要：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.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.

关 键 词：metallic materials two-way shape memory spring thermomechanical training different scanning calorimetry (DSC) electrothermal driving 

分 类 号：TG139.6[一般工业技术—材料科学与工程] TH135[金属学及工艺—合金]