Influence of microstructural purity on the bending fatigue behavior of VAR-melted superelastic Nitinol.

The bending fatigue resistance of commercially-available Standard versus High Purity Nitinol was evaluated at 3% mean strain and a range of strain amplitudes with the simple wire Z-specimen geometry. The Standard grade Nitinol demonstrated a 10(7)-cycle fatigue strain limit of 0.50% alternating strain, comparable to results reported elsewhere in the literature.