Friction testing of tube-guided electrically heated Nitinol shape-memory alloy wires

In this study, a test scenario for the friction testing of electrically heated shape-memory alloy (SMA) wires against polymer surfaces was developed. As alloy, Nickel-Titanium (Nitinol, NiTi) was specially selected due to its high working capacity, the good corrosion resistance and the quick actor response at low bias forces. As the materials in contact with the actuator must resist friction forces and elevated temperatures up to 200 degrees C, a combination with high performance polymers is preferable. In many applications, the actuators use redirections to enhance the actuator capabilities or enable the use in complex structures. To better understand and compare the tribological properties of Nitinol against various polymer materials, it was needed to manufacture a customized testing device.