Preliminary Results of Stress Recovery of Constrained NiTi SMA Wire for Aerospace Applications
The rocket propellant ignition system uses electro-explosive device actuated by wire electrode. Those wires are usually made by Fe-Ni based alloy with controlled thermal expansion inserted into a ceramic feed-through and are connected to thin resistive wire which is heated through the passage of an electrical current for propellant ignition. The contact between ceramic feed-through and wires should be reliable since sometimes it could fail. A novel alternative process is to use SMA wires taking into account the shape recovery effect constraining the wire inside the feed-through. The recovery stress of 326 MPa for 4% pre-strain should be enough to constrain the wire inside the feed-trough avoiding the gas leakage.
Rodinei M. Gomes, Silvio de Barros, Sandro M. Torres, Severino Jackson G. de Lima, Tadeu A. A. Melo, Vicente T. Lopes Buono
J. C. Santos et al., "Preliminary Results of Stress Recovery of Constrained NiTi SMA Wire for Aerospace Applications", Materials Science Forum, Vol. 643, pp. 15-18, 2010