Abstract: A metallic seal having a continuous annulus of Nitinol that is compressed between two seal faces and conforms to the minute irregularities of the seal faces to prevent leakage of fluid through those irregularities at extreme conditions of temperature, pressure and chemically reactive environments.

Abstract: A replacement for the conventional pyrotechnic separation device for large structural elements such as payload fairings on large missile systems is a sequence of nitinol wires or foil strips which, because of their high strength, will hold the structures together but, when heated electrically in sequence, will fuse in milliseconds to allow the structures to separate. The technique for fusing the wires sequentially is to provide wires of sequentially increasing lengths which will cause the shorter length, lower resistance wires to fuse first and the successively longer wires to fuse in sequence until all wires are fused.

Abstract: A method for creating an elongate passage of a desired cross-sectional shape and size within a component. A shape memory metal alloy is formed into an elongate element, such as a wire (16), having the cross-sectional shape and size desired of the elongate passage. The wire is embedded within a component (10) as the component is manufactured, e.g., by laying-up the component from a fiber/resin composite and curing it, or by casting the component in a mold (50) from a liquid that hardens around the memory metal alloy, embedding it in place. The liquid may comprise glass, ceramic, thermoplastic, or metal having a lower melting point than the memory metal alloy. The wire is then pulled from the component, by applying a force sufficient to convert the memory metal alloy from a soft martensitic state to a stress-induced martensitic state, thereby plastically and inelastically deforming it so that it lengthens. As the memory metal alloy wire lengthens, its cross-sectional area decreases.

Abstract: A shape memory alloy used for both sensing and damping vibration of a structure. In one embodiment, a flat bar (12) is mounted from one end on its edge so that its other end vibrates from side-to-side at its natural resonant frequency. A vibration damping wire (30) extending longitudinally along one surface of the bar is mounted under tension between spaced apart standoffs (32); a sense wire (42) is similarly mounted along the opposite surface of the bar. The vibration damping wire and sense wire comprise a nickel-titanium (Nitinol) alloy, having a relatively high specific damping coefficient. Absorption of kinetic energy by the vibration damping wire when it is stretched by deflection of the bar greatly reduces the time required to passively damp vibration of the bar, compared to its undamped resonant time. the vibration damping wire is heated above a transition temperature by an electrical current pulse while relaxed to restore it to its unstretched length.