Abstract: A process for diffusion bonding a coating of Nitinol intermetallic compound to a surface of a metallic substrate includes heating and cleaning the surface of the substrate to a metallurgically clean condition by creating a plasma arc in a plasmatron and partially ionizing and heating a stream of inert gas in the plasma arc. The stream of partially ionized gas from the plasmatron is directed to the surface of the substrate to remove oxides and other contaminants from the surface. Nitinol powder is entrained in a mixture of hydrogen and argon gasses heated and ionized in the plasmatron, thereby heating the powder to a partially molten state. The partially molten power is ejected in the gas mixture from the plasmatron at high velocity and impacts against the metallurgically clean heated substrate surface to produce a diffusion bond between the Nitinol intermetallic compound and the metal substrate.

Abstract: A method high security locking includes inserting a shackle having two ends into a lock body having openings for receiving the ends of the shackle. A latch in the lock body has a catch that snaps into engagement with the shackle for securing at least one end of the shackle in the body. The latch may be released to allow the one end of the shackle to move clear of the body. to open the lock. The shackle is made of a shape memory effect alloy having a characteristic that its yield strength increases when work is impressed on it, so that cutting or breaking the shackle with common tools is more difficult and time consuming than with other shackle materials. The lock thus provides a level of security substantially superior to conventional locks.

Abstract: A gun barrel for a gun has an elongated tube with an axial bore extending completely through the tube from the breech end to the muzzle end. The tube and the contact surface in the axial bore, which contains propellant gasses behind the projectile and engages the projectile while guiding it toward the target, are made of Nitinol having a transition temperature lower than the lowest ambient temperature at which a gun with the barrel is designed to be operated, or of a Nitinol formulation consisting essentially of 60% nickel and 40% titanium. A first sleeve may be mechanically coupled to the barrel tube by shape memory contraction thereon to prestress the barrel tube in compression.

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.

Abstract: A shape memory metal actuator for accurately pointing or aligning a moveable piece of equipment or other object. The memory metal components (12, 14, 16, 18) are stretched along their axes and arranged in a push-pull configuration so that one element (14) in the activated state moves the object while another element (18) on the opposite side of the object is strained while it is in the soft state to act as a dynamic damper to prevent overtravel of the object. The wires can be heated with external heaters or by electrical current passed directly therethrough. Two separate actuator assemblies using orthogonal pairs of shaped memory metal wires (42, 44, 46, 48 and 52, 54, 56, 58) are used to enable pivotal movement about a floating pivot point 41, while a cantilevered arrangement of Nitinol bars (88, 90, 92 and 94) are used to enable pivotal movement about a fixed flexure point F.