Fretting damage of Ni-rich ultrafine grained NiTi superelastic wires.

The effects of fretting on Ni-rich ultra-fine grained NiTi superelastic wires have been characterized. Fretting tests have been performed using wire on wire in 90° cross-cylinder configuration until 10 cycles in air at 25 °C. Constant displacement amplitude of 50 µm and normal loads of 10, 20 and 50 N were considered.