Some kinds of titanium-nickel springs with shape memory effect were investigated in their mechanical properties under various temperature and strain. The load of the titanium-nickel spring had non-linearity and dependence on the temperature. And it also had some hysteresis to the change of the deviation and the temperature, which increased with the increase of the strain given to the spring.
The experimental results were compared with the values calculated from the stress-strain property of the wire. There were some differences between them.