In situ Neutron Diffraction Study on the Effect of Annealing Treatment on Phase Analysis of Nitinol during Thermal and Mechanical Cycling

Nitinol (nickel-titanium alloy), which belongs to one of categories of shape memory alloy, has drawn significant attention from scientific community and industry for their wide applications in medical (blood vessel stents) and aerospace (satelllite and jet engine). Nitinol can repeatedly recover large strains (over 8%) through phase transformation. Of interest of this proposal is to investigate annealing effect on phase tranformation during both thermal and mechanical cycling of Nitinol wire, thus filling the gap in existing knowledge. The reserach out come will substantially improve the performance of shape memory alloy actuators in broad applications and bring impact to industry.