Effect of Current on Electrothermal Driving Characteristics of NiTiCu Shape Memory Alloy Wire

The effects of current and its loading time on the deformation rate and deformation time of NiTiCu shape memory alloy wire were investigated by loading different current levels into the alloy wire, and then the empirical formula of the current and deformation time was obtained. The results show that the deformation time of the alloy wire first decreased rapidly with the increase of current then tended to be stable when the current increased to a certain value. Under the same current, with the increase of current loading time, the deformation angle of the alloy wire first increased slowly then rapidly, and finally tended to be stable, indicating the first increased then decreased deformation rate of the alloy wire. The calculated curves by the empirical formula of the current and deformation time agreed well with the tested data.