Composite alloys comprising a first alloy portion comprising nickel and titanium and a second alloy portion comprising nickel and titanium in a different stoichiometry than the first alloy portion are disclosed, along with related methods of manufacture and use. Particularly, the composite alloys may be used in customized medical devices where a shape memory effect would be beneficial.

A fatigue-resistant Nitinol instrument has a working portion in the deformed monoclinic martensitic state and an austenite finish temperature in the range of 40 to 60 C. Because the operating environment of the instrument is about 37 C., the working portion remains in the monoclinic martensitic state during its use. The relatively high austenite finish temperature and fatigue resistance is achieved by subjecting the nickel-titanium alloy to a final thermal heat treat in a temperature range of about 410 to 440 C. while the nickel-titanium alloy is under constant strain of about 3 to 15 kg. Further, the high austenite finish temperature is achieved without subjecting the alloy to thermal cycling to produce shape memory. Additionally, there are no intermediate processing steps occurring between obtaining a finished diameter of the wire or blank through cold working and the final thermal heat treat under constant strain.

An orthodontic bracket and archform system that uses friction-free mechanics are disclosed. The archform can have a male fastener that can be retained within an orthodontic bracket. The orthodontic bracket can have varying locking mechanism, such as deflectable tabs, springs, locking pins, and others, that can cooperate with features of the male fastener to prevent sliding between the archform and the bracket.

Shapeable guide wire devices and methods for their manufacture. Guide wire devices include an elongate shaft member having a shapeable distal end section that is formed from a linear pseudoelastic nickel-titanium (NiTi) alloy that has linear pseudoelastic behavior without a phase transformation or onset of stress-induced martensite. Linear pseudoelastic NiTi alloy, which is distinct from non-linear pseudoelastic (i.e., superelastic) NiTi alloy, is highly durable, corrosion resistant, and has high stiffness. The shapeable distal end section is shapeable by a user to facilitate guiding the guide wire through tortuous anatomy. In addition, linear pseudoelastic NiTi alloy is more durable tip material than other shapeable tip materials such as stainless steel.

An earth-boring tool includes a tool body, at least one cutting element, and a retaining member comprising a shape memory material (e.g., alloy, polymer, etc.) located between a surface of the tool body and a surface of the cutting element. The shape memory material is configured to transform, responsive to application of a stimulus, from a first solid phase to a second solid phase. The retaining member comprises the shape memory material in the second solid phase, and at least partially retains the at least one cutting element adjacent the tool body. The shape memory material may be trained in a first phase to a first shape, and trained in a second phase to a second shape. The retaining member may be at least partially within a cavity in the first phase, then transformed to the second phase to apply a force securing the cutting element to the tool body.

Problem To provide a heat resistant metal gasket that is controlled to have a strength level (ordinary temperature hardness) capable of facilitating processing, and has excellent gas leak resistance.

Solution An austenitic stainless steel sheet for a metal gasket, having a chemical composition containing from 0.015 to 0.200% of C, from 1.50 to 5.00% of Si, from 0.30 to 2.50% of Mn, from 7.0 to 17.0% of Ni, from 13.0 to 23.0% of Cr, and from 0.005 to 0.250% of N, all in terms of percentage by mass, containing, as necessary, at least one of Mo, Cu, Nb, Ti, V, Zr, W, Co, B, Al, REM (rare-earth element except for Y), Y, Ca and Mg, with the balance of Fe and unavoidable impurities, having an ordinary temperature hardness of 430 HV or less, having a half width of a peak of an austenite crystal (311) plane in an X-ray diffraction pattern of a cross section perpendicular to a sheet thickness direction of from 0.10 to 1.60, and having a surface roughness Ra of 0.30 mm or less.

The invention relates to a method for manufacturing a titanium alloy having superelastic properties and/or shape memory for biomedical use, which comprises the steps of: preparing an ingot by melting the various metals that form the desired alloy in a vacuum; optionally homogenizing the ingot in a vacuum by high-temperature annealing (higher than 900 C.); first quenching; mechanical shaping (rolling, drawing, machining or the like); heat treatment for redissolution in beta phase beyond the beta transus temperature (until a second temperature and then maintaining same for a certain time); and second quenching; characterized in that said heat treatment phase is carried out in a gaseous atmosphere and also constitutes a surface treatment suitable for forming on the surface a layer of nitride, carbonitride, oxide, oxynitride or the like.

A monolithic titanium alloy having, in a temperature range (T) and at atmospheric pressure: an outer peripheral zone of a microstructure having a modulus of elasticity (E.sub.1) and possessing superelastic properties in the range (T), and a core of a microstructure having a modulus of elasticity (E.sub.2), and possessing elastic properties in the range (T); the microstructures and being different from one another, and the modulus of elasticity (E.sub.1) being lower than said modulus of elasticity (E.sub.2).

A thermal seal may include a flexible insulation layer, and an element made of shape memory alloy attached to the insulation layer, the element being treated to bend in response to heating, whereby an increase in the temperature of the element causes the insulation layer to transform from a first configuration to a second configuration.

A concrete product comprising an adaptive prestressing system includes a concrete body and a composite wire embedded within the concrete body at a predetermined location. The composite wire comprises anchored end portions, each of which comprises a bonded wire segment constrained within the concrete body to resist axial motion, and an activable central portion between the end portions. The activable central portion comprises a shape memory alloy (SMA) wire segment and is axially movable within the concrete body. When heated at or above an austenite transformation temperature, the SMA wire segment contracts and the activable central portion exerts a tensile force on the end portions, thereby applying a compressive prestress within the concrete body at the predetermined location.