NiMnGa合金磁控形状记忆效应及外特性

系统地阐述了铁磁NiMnGa合金的微结构、相变机理、形状记忆效应，并对NiMnGa磁控形状记忆合金的外特性进行了实验研究，得出了磁场、温度、预压力与NiMnGa合金形变率之间的静态关系，绘制了不同温度和预压力下的动态曲线，得比了静态形变率和动态形变率的变化规律。实验结果证明，NiMnGa合金变形率随预压力的增大而减小；随磁场强度的增大而增大；当温度接近向奥氏体转变温度时，形变率最大；这为NiMnGa合金的实际应用打下了理论和实验基础。

Magnetic Shape Memory Effect and External Characteristic of NiMnGa Alloy

The paper introduced microstructure, transition mechanism, shape memory effect of ferromagnetic NiMnGa system, and systematically examined external characteristic of NiMnGa magnetic shape memory alloy. The static relationships of magnetic field, temperature, pre-pressure, strain of NiMnGa were obtained. After drawing the dynamic curves of different temperature and pre-pressure, the characteristic features of NiMnGa dynamic strain and static strain were given. The experimental results confirm that with the increase of magnetic field and decrease of pre-pressure, the strain inerease. When the temperature close to austensite temperature, the strain is the largest. Therefore, the results provide a theoretical and experimental basis for practical application of NiMnGa alloy.