用于智能材料与结构的 NiTi 丝的电阻特性研究

Study on the Resistance of NiTi Wire Applied in Intelligent Materials System and Structure

研究了拉伸过程中，ＮｉＴｉ形状记忆合金丝的应变与电阻的关系．结果表明，对于初始组织为马氏体的ＮｉＴｉ丝，在拉伸过程中，电阻与应变之间成线性关系．对于初始组织为奥氏体或奥氏马氏体两者混合的ＮｉＴｉ丝，当发生应力诱发马氏体相变后，曲线的斜率降低，相变前后电阻－应变保持线性关系．对于初始组织含有Ｒ相组织的ＮｉＴｉ丝，在拉伸过程中，电阻的变化规律较为复杂，取决于初始组织中各相的比例和温度．在卸载阶段，当没有相变过程发生时，电阻－应变之间呈线性关系；当有相变过程发生时，电阻－应变曲线的斜率会发生改变．

In order to apply shape memory alloys to intelligent materials and structures as sensors, the relationship between the strain and electric resistance for Nitinol under tension is studied. The results show that the electric resistance increases linearly with the increase of strain if the original microstructure is Martensitic. So, it is possible to apply NiTi wires in one structure as both actuators and sensors.