Abstract: A copper-based alloy material including a multiphase structure containing a matrix of a ? phase and a precipitation phase of a B2-type crystal structure dispersed in the matrix, where the copper-based alloy material includes a composition containing 8.6 to 12.6% by mass of Al, 2.9 to 8.9% by mass of Mn, 3.2 to 10.0% by mass of Ni, and Cu.

Abstract: An epicyclic gearbox is configured to transfer rotational motion between a first rotating component and a second rotating component of the gas turbine engine. The gearbox includes a centrally located sun gear, two or more planet gears circumscribing the sun gear, and a ring gear circumscribing the plurality of planet gears. The gearbox is configured such that the sun gear is drivingly coupled to the first rotating component, such that rotation of the sun gear causes rotation of each planet gear, and such that the ring gear rotates relative to the plurality of planet gears. The gearbox includes one or more shape memory alloy dampers provided in association with the sun gear, the ring gear, and/or the plurality of planet gears. The shape memory alloy damper(s) is configured in order to reduce vibrations transferred through the epicyclic gearbox to the frame, the first rotating component, and/or the second rotating component.

Abstract: A gas turbine engine includes a compressor section and a turbine section arranged in serial flow order. A shaft is provided rotatable with at least a portion of the compressor section and with at least a portion of the turbine section. A bearing is also provided supporting rotation of the shaft, with a support element in turn supporting the bearing. The gas turbine engine also includes a superelastic member formed of a shape memory alloy supporting at least one of the support element or the bearing. The superelastic member is installed in a pre-stressed condition to enhance a dampening function of the superelastic member.

Abstract: Systems and methods disclosed herein relate to the manufacture of metallic material with a thermal expansion coefficient in a predetermined range, comprising: deforming, a metallic material comprising a first phase and a first thermal expansion coefficient. In response to the deformation, at least some of the first phase is transformed into a second phase, wherein the second phase comprises martensite, and orienting the metallic material in at least one predetermined orientation, wherein the metallic material, subsequent to deformation, comprises a second thermal expansion coefficient, wherein the second thermal expansion coefficient is within a predetermined range, and wherein the thermal expansion is in at least one predetermined direction. In some embodiments, the metallic material comprises the second phase and is thermo-mechanically deformed to orient the grains in at least one direction.

Abstract: A fastener retention system for retaining fasteners within apertures of an orthopedic plate includes a first pocket disposed between two of the apertures in the plate, a blocking member disposed between the two apertures and including a second pocket that forms a cavity with the first pocket, and a spring that expands from a compressed configuration within the first pocket to a decompressed configuration within the cavity.

Abstract: A method of making a self-expanding stent entails applying a bend stress sufficient to over-bend a portion of a wire by an amount in a range from about 85% to about 105%, where the wire comprises a Ni—Ti alloy and includes from about 40% to about 46% cold work. The bend stress is then released, thereby forming a bend having a predetermined bend angle in the wire. The application and release of the bend stress are repeated on successive portions of the wire in order to create a series of bends along a length of the wire in a predetermined bend pattern. The wire comprising the predetermined bend pattern is then positioned about a mandrel in an expanded stent geometry and heat set. Thus, a self-expanding stent is formed.

Abstract: [PROBLEM] The invention provides a roll for hot rolling process having various types of more excellent durability performances than conventional rolls, and provides also a method for manufacturing the same. [SOLUTION] A cladding layer 4 is formed on an outer circumference portion of a roll for hot rolling process 1, where the cladding layer 4 comprises: 0.5 to 0.7% by mass of C, 2.8 to 4.0% by mass of Si, 0.9 to 1.1% by mass of Cu, 1.4 to 1.6% by mass of Mn, 2.7 to 3.3% by mass of Ni, 13.5 to 14.5% by mass of Cr, 0.8 to 1.1% by mass of Mo, 0.9 to 1.1% by mass of Co, and 0.2 to 0.4% by mass of Nb, with a balance being Fe and inevitable impurities, and has a thickness of 5 mm or more.

Abstract: A method of improving the fatigue life of a superelastic medical device includes applying a compressive stress to a fatigue critical location of a medical device comprising a superelastic nickel-titanium alloy, where the compressive stress induces a compressive strain of greater than 9% in the fatigue critical location. After inducing the compressive strain, the compressive stress is released. A tensile stress is applied to the fatigue critical location of the medical device, where the tensile stress induces a tensile strain of greater than 9% in the fatigue critical location. After inducing the tensile strain, the tensile stress is released. After application and release of each of the compressive stress and the tensile stress, the fatigue critical location includes a non-zero amount of residual strain, and the medical device may exhibit improved fatigue properties.

Abstract: A Cu—Al—Mn-based alloy material (1) having a composition comprising: given contents of Al and Mn, and a given total content of at least one selected from Ni and the like; with the balance being Cu and unavoidable impurities, wherein the alloy material has a shape elongated in the working direction (RD), wherein a grain length ax in the RD is R/2 or less to the width or diameter (R), a grain length bx in a direction perpendicular to the RD is R/4 or less, and the amount of grains X (2) is 15% or less, and wherein a grain length a in the RD and a grain length b in the direction perpendicular to the RD satisfy: a?b, and an angle formed by the normal line of the (111) plane and the RD is 15° or larger, the amount of grains Y? (3) is 85% or more.

Abstract: A closure component of a tank of a motor vehicle for closing a filler neck gas- and fluid-tight, having a closure fastened to a flap, the flap being fastened to a vehicle body of the motor vehicle such that it is movable into an open or closed position, the closure including a seal, which causes the closure to close against the filler neck. The tank closure should be easy for a user to handle and have a relatively simple design and be economical to manufacture. This is achieved in that the seal is electromechanically or pneumatically adjustable with the aid of an actuator.

Abstract: Wire products, such as round and flat wire, strands, cables, and tubing, are made from a shape memory material in which inherent defects within the material are isolated from the bulk material phase of the material within one or more stabilized material phases, such that the wire product demonstrates improved fatigue resistance. In one application, a method of mechanical conditioning in accordance with the present disclosure isolates inherent defects in nickel-titanium or NiTi materials in fields of a secondary material phase that are resistant to crack initiation and/or propagation, such as a martensite phase, while the remainder of the surrounding defect-free material remains in a primary or parent material phase, such as an austenite phase, whereby the overall superelastic nature of the material is preserved.

Abstract: A lockable latching device includes a body defining a cavity and a plunger disposed within a cavity defined in the body. The plunger is translatable with respect to the body between an open position and a closed position. The lockable latching device also includes an annular rotator configured for rotating the plunger about a central longitudinal axis, and an annular latch transitionable between an unlocked state and a locked state. The lockable latching device further includes first and second elements. The lockable latching device also includes a force transmission mechanism operably connected to the first element, the second element, and the annular latch, with the force transmission mechanism configured to transition the annular latch from the unlocked state to the locked state in response to a first activation signal, and to transition the annular latch from the locked state to the unlocked state in response to a second activation signal.

Abstract: A hybrid bearing support system includes a shaft extension fixedly coupled to a rotatable member at a radial inner end of the shaft extension, a radial outer end of the shaft extension fixedly coupled to a rotatable race of a bearing supporting the rotatable member, and a recoupler device formed of a shape memory alloy (SMA) material coupled in parallel with at least a portion of the shaft extension between the radial inner end and the radial outer end.

Abstract: An apparatus and related method for controlling a load on a human ankle joint during normal gait while preserving motion. The approach is intended to treat osteoarthritis and pain of the ankle without substantially resisting an angular displacement associated with full mobility of the ankle joint. In one particular embodiment, the device includes a first load transmission support, a second load transmission support and an implantable compressible absorber.

Abstract: A tube for a steerable introduction element like a catheter, an endoscope or a sheath includes composite material of a shape memory alloy material and a non-shape-memory polymer material. The tube is used for making the introduction element steerable in a relatively easy way by modifying the temperature of the tube as required for achieving a preferred bending of the introduction element.

Abstract: A tire includes a plurality of SMA springs. Each SMA spring includes a first end portion, a second end portion, and an arching middle portion. Each SMA spring is interlaced with at least one other SMA spring thereby forming a laced toroidal structure extending about an entire circumference of the tire.

Abstract: A method and apparatus for the treatment of OSA are disclosed which protrudes the tongue and hence enlarges the pharyngeal cross-sectional area by implanting a state changing actuator, one leg inserted helically directly into the root of the tongue near the hyoid bone, along and near the base of the tongue into the body of the tongue, the section leaving the root of the tongue providing a torque (tending to expand the V-shape of the implant), the other leg acting as a force distribution placed between the root of the tongue and the geniohyoid, or between geniohyoid and mylohyoid. Another embodiment shows placement of a passive implant to permanently compress the tongue by deforming it providing a force compressing the tongue, the force directed toward the axis of the helix, hence protruding the tongue to enlarge the pharyngeal cross-sectional passageway to prevent obstructions of the airway.

Abstract: The present invention relates to Cu33Al17 alloys and Cu33Al17-based bulk alloys and coatings that exhibit significantly increased hardness characteristics compared to traditional copper-aluminum alloys.

Abstract: A rotor support system for a gas turbine engine may generally include a bearing assembly and a load reduction member configured to be coupled between the bearing assembly and a support frame of the engine. The load reduction member may include a fuse portion configured to fail when a load transmitted through the load reduction member exceeds a predetermined load threshold. The system may also include a load recoupling member provided between the bearing assembly and the support frame. The load recoupling member may be formed from a super-elastic shape memory alloy that allows the load recoupling member to undergo recoverable deformation without failing when the fuse portion fails such that the load recoupling member maintains a mechanical connection between the bearing assembly and the support frame.

Abstract: There is provided herein a shape memory alloy wire that includes an alloy composition of CuAlMnNi and excluding grain refiner elements. The alloy composition includes 20 at %-28 at % Al, 2 at %-4 at % Ni, 3 at %-5 at % Mn with Cu as a remaining balance of the alloy composition. The alloy composition is disposed as an elongated wire of at least about 1 meter in length, having a wire diameter of less than about 150 microns. At least about 50 vol % of said alloy composition along said wire length has an oligocrystalline microstructure as-disposed in the wire and without thermal treatment of the wire.

Abstract: The method for improvement of Nitinol fatigue fracture resistance may be accomplished by electropolishing or magnetoelectropolishing under oxygen evolution regime, and by anodizing or magnetoanodizing the intermetallic compound. All four processes are performed under an oxygen evolution regime and by these processes the outermost and subsequent underlying oxide layers are enriched with oxygen which saturates, fills oxygen vacancies and bridges surface oxide lattice defects making the passive oxide layer more stoichiometric and homogenous, elastic and, as a result of the oxygen enrichment, more fatigue fracture resistant.

Abstract: A lockable latching device includes a body defining a cavity therein and having a central longitudinal axis, and a plunger disposed within the cavity. The plunger has a first end and a second end and is translatable with respect to the body along the axis between an open position and a closed position. The device also includes an annular rotator spaced apart from the body along the axis and configured for rotating the plunger about the axis. The device includes an annular latch abutting the rotator that is transitionable between an unlocked state and a locked state. The device also includes an element attached to the latch and formed from a shape memory alloy that is transitionable between an austenite crystallographic phase and a martensite crystallographic phase in response to an activation signal to thereby transition the latch from the locked state to the unlocked state.

Abstract: A method for retreading a wheel tire casing: a wheel tire casing is induction heated so as to soften a thermally malleable layer located between a tread of the casing and a carcass of the casing, the tread is removed from the carcass, and another tread is applied to the carcass.

Abstract: A well drilling system can include a drilling tool with at least one component which is displaced by a material that changes shape. The material can be a shape memory material. The material may change shape in response to a temperature change. The component can be a drill bit cutter, a depth of cut control surface, a gauge surface or a stabilizer surface. A method of controlling a drilling operation can include configuring a drilling tool with a material which changes shape, and the material displacing at least one component of the drilling tool during the drilling operation. Displacement of the component can be controlled downhole to maintain drilling parameters (such as torque, vibration, steering performance, etc.) in desired ranges.

Abstract: A flow diverter is described and fabricated using ultra-thin porous thin-film Nitinol, and is configured for implantation to a treatment site within a vessel for significant reduction in an intra-aneurismal flow velocity and vorticity. Using small size pores in a coverage area of only 10%, a 90% reduction in flow velocity into a pseudo-aneurysm can be achieved, with an almost immediate cessation of flow into an anatomical feature such as aneurysm sac in vivo. The size of the holes can be tailored to be any shape and range in size from 1-400 ?m using photolithography and from 5-1000 nm using ebeam lithography.

Abstract: 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 (Ni—Ti) alloy that has linear pseudoelastic behavior without a phase transformation or onset of stress-induced martensite. Linear pseudoelastic Ni—Ti alloy, which is distinct from non-linear pseudoelastic (i.e., superelastic) Ni—Ti 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 Ni—Ti alloy is more durable tip material than other shapeable tip materials such as stainless steel.

Abstract: A method for controlling a device using a shape-memory alloy wire is disclosed. The method includes determining an ontime for the shape-memory alloy wire based on a target volume to be pumped by a pump plunger, determining the temperature of the shape-memory alloy wire and adjusting the ontime based on the temperature of the shape-memory alloy wire.

Abstract: The present invention relates to a method of determining both pressures and temperatures in a high temperature environment. The present invention also relates to a method of determining temperatures about a pressure-sensing element using a bi-functional heater. In addition, the present invention preferably relates to a pressure sensor with the pressure-sensing element and a heating element both integrated into the sensor's packaging, preferably onto the diaphragm of the pressure sensor, and particularly to such a pressure sensor capable of operating at high or elevated temperatures, and even more particularly to such a pressure sensor wherein the heating element is capable of both heating, at least in part, the pressure-sensing element and monitoring the temperature of the application area. Preferably, the pressure-sensing element is formed from shape memory alloy (SMA) materials that can be used at high or elevated temperatures as a pressure sensor with high sensitivity.

Abstract: High-strength brass alloy having superior wear maintains single-structure ? phase and Fe—Cr—Si-based intermetallic compounds dispersed in the ? phase. A high-strength brass alloy for sliding member comprises Zn from 17% to 28%, Al from 3% to 10%, Fe from 1% to 4%, Cr from 0.1% to 4%, Si from 0.5% to 3%, mass ratio, and the remnant including Cu and inevitable impurities. The high-strength brass alloy has structure in which the matrix shows single-phase structure of ? phase and Fe—Cr—Si-based intermetallic compounds are dispersed in the ? phase. The high-strength brass alloy for sliding member has the structure in which the matrix shows single-structure of ? phase and hard Fe—Cr—Si-based intermetallic compounds are dispersed in the ? phase. Thus the hardness is increased and wear resistance is improved.

Abstract: Ratcheting shape memory alloy actuators and systems and methods including the same are disclosed herein. The ratcheting shape memory alloy actuators include a ratcheting assembly that is operatively coupled to a first bracket and a shape memory alloy element that is operatively coupled to the ratcheting assembly and to a second bracket. The first bracket is configured to be operatively coupled to a first structure, while the second bracket is configured to be operatively coupled to a second structure. The shape memory alloy element is configured to apply a motive force to the ratcheting assembly upon deformation between a first conformation and a second conformation. The ratcheting assembly is configured to utilize the motive force to selectively adjust an orientation of the first structure relative to the second structure.

Abstract: Medical devices that include a Ni—Ti ternary alloy and methods for their manufacture. The medical devices described herein include at least one part fabricated from the Ni—Ti ternary alloy. In the Ni—Ti alloys, the ternary alloying element is selected to be compatible with Ni—Ti. Example Ni—Ti ternary alloys include nickel (Ni), titanium (Ti), and one or more of tantalum (Ta), hafnium (Hf), vanadium (V), zirconium (Zr), scandium (Sc), or yttrium (Y). By virtue of their compatibility with Ni—Ti, additions of the ternary alloying element(s) may substitute for titanium in the Ni—Ti phase up to the solubility of the ternary element and the remainder can exist as a second phase whose mechanical properties resemble that of the pure ternary element and whose elastic modulus exceeds that of the Ni—Ti matrix.

Abstract: A gas turbine engine (10) includes a fan (14), a nacelle (28) arranged about the fan, and an engine core at least partially within the nacelle. A fan bypass passage (30) downstream of the fan between the nacelle and the gas turbine engine conveys a bypass airflow (1) from the fan. A nozzle (40) associated with the fan bypass passage is operative to control the bypass airflow. The nozzle includes a shape memory material having a first solid state phase that corresponds to a first nozzle position and a second solid state phase that corresponds to a second nozzle position.

Abstract: Methods and apparatuses for stabilizing the strain-temperature response for a shape memory alloy are provided. To perform stabilization of a second sample of the shape memory alloy, a first sample of the shape memory alloy is selected for isobaric treatment and the second sample is selected for isothermal treatment. When applying the isobaric treatment to the first sample, a constant stress is applied to the first sample. Temperature is also cycled from a minimum temperature to a maximum temperature until a strain on the first sample stabilizes. Once the strain on the first sample stabilizes, the isothermal treatment is performed on the second sample. During isothermal treatment, different levels of stress on the second sample are applied until a strain on the second sample matches the stabilized strain on the first sample.

Abstract: A material for use as a mechanical component is formed of a superelastic intermetallic material having a low apparent modulus and a high hardness. The superelastic intermetallic material is conditioned to be dimensionally stable, devoid of any shape memory effect and have a stable superelastic response without irrecoverable deformation while exhibiting strains of at least 3%. The method of conditioning the superelastic intermetallic material is described. Another embodiment relates to lightweight materials known as ordered intermetallics that perform well in sliding wear applications using conventional liquid lubricants and are therefore suitable for resilient, high performance mechanical components such as gears and bearings.

Abstract: A device having a first part shrink-fitted with a first shrink ring, the first shrink ring being shrink-fitted with a second shrink ring exhibiting a lower thermal expansion coefficient than a thermal expansion coefficient of the first shrink ring.

Abstract: A mechanical structure is provided with a crystalline superelastic alloy that is characterized by an average grain size and that exhibits a martensitic phase transformation resulting from a mechanical stress input greater than a characteristic first critical stress. A configuration of the superelastic alloy is provided with a geometric structural feature of the alloy that has an extent that is no greater than about 200 micrometers and that is no larger than the average grain size of the alloy. This geometric feature undergoes the martensitic transformation without intergranular fracture of the geometric feature.

Abstract: The method for surface inclusions detection, enhancement of endothelial and osteoblast cells adhesion and proliferation and sterilization of electropolished and magnetoelectropolished Nitinol implantable medical device surfaces uses an aqueous solution of chemical compounds containing halogenous oxyanions as hypochlorite (ClO?) and hypobromite (BrO?) preferentially 6% sodium hypochlorite (NaClO).

Abstract: A high temperature component having an actuator body including an actuatable portion comprising a shape memory alloy containing one more of Ni, Al, Nb, Ti and Ta and a platinum-group metal. The shape memory alloy has an altered geometry at a predetermined temperature. The actuator is also capable of operation in and is resistant to high temperature oxidizing atmospheres. A method for forming an actuator and a method for high temperature control are also disclosed.

Abstract: A mechanical structure is provided with a crystalline superelastic alloy that is characterized by an average grain size and that exhibits a martensitic phase transformation resulting from a mechanical stress input greater than a characteristic first critical stress. A configuration of the superelastic alloy is provided with a geometric structural feature of the alloy that has an extent that is no greater than about 200 micrometers and that is no larger than the average grain size of the alloy. This geometric feature undergoes the martensitic transformation without intergranular fracture of the geometric feature.

Abstract: A heat engine includes a first rotatable pulley and a second rotatable pulley spaced from the first rotatable pulley. A shape memory alloy (SMA) element is disposed about respective portions of the pulleys at an SMA pulley ratio. The SMA element includes a first wire, a second wire, and a matrix joining the first wire and the second wire. The first wire and the second wire are in contact with the pulleys, but the matrix is not in contact with the pulleys. A timing cable is disposed about respective portions of the pulleys at a timing pulley ratio, which is different than the SMA pulley ratio. The SMA element converts a thermal energy gradient between the hot region and the cold region into mechanical energy.

Abstract: Medical devices that include a Ni—Ti ternary alloy and methods for their manufacture. The medical devices described herein include at least one part fabricated from the Ni—Ti ternary alloy. In the Ni—Ti alloys, the ternary alloying element is selected to be compatible with Ni—Ti. Example Ni—Ti ternary alloys include nickel (Ni), titanium (Ti), and one or more of tantalum (Ta), hafnium (Hf), vanadium (V), zirconium (Zr), scandium (Sc), or yttrium (Y). By virtue of their compatibility with Ni—Ti, additions of the ternary alloying element(s) may substitute for titanium in the Ni—Ti phase up to the solubility of the ternary element and the remainder can exist as a second phase whose mechanical properties resemble that of the pure ternary element and whose elastic modulus exceeds that of the Ni—Ti matrix.

Abstract: An Fe-based shape memory alloy comprising 25-42 atomic % of Mn, 12-18 atomic % of Al, and 5-12 atomic % of Ni, the balance being Fe and inevitable impurities, and an Fe-based shape memory alloy comprising 25-42 atomic % of Mn, 12-18 atomic % of Al, and 5-12 atomic % of Ni, as well as 15 atomic % or less in total of at least one selected from the group consisting of 0.1-5 atomic % of Si, 0.1-5 atomic % of Ti, 0.1-5 atomic % of V, 0.1-5 atomic % of Cr, 0.1-5 atomic % of Co, 0.1-5 atomic % of Cu, 0.1-5 atomic % of Mo, 0.1-5 atomic % of W, 0.001-1 atomic % of B and 0.001-1 atomic % of C, the balance being Fe and inevitable impurities.

Abstract: A radiopaque alloy based on titanium nickelide and having shape memory and superelastic properties includes, according to one embodiment, at least one radiopaque alloying element selected from among gold, platinum, and palladium at a concentration of from about 10 at. % to about 20 at. %, and at least one additional alloying element selected from among aluminum, chromium, cobalt, iron, and zirconium, where the additional alloying element has a concentration of from about 0.5 at. % to about 4 at. %. The alloy includes titanium at a concentration of from about 48 at. % to about 52 at. %, and the balance of the alloy is nickel. The radiopaque alloy preferably exhibits superelastic behavior suitable for medical device applications in the human body.

Abstract: A device and method for controlling a phase transformation temperature of a shape memory alloy is provided. The device includes a primary wire composed of the shape memory alloy. The primary wire defines first and second ends, the first end being attached to a fixed structure and the second end being able to displace. An activation source is thermally coupled to the wire and is operable to selectively cause the primary wire to reversibly transform from a Martensitic phase to an Austenitic phase during a cycle. A loading element is operatively connected to the primary wire and configured to selectively increase a tensile load on the primary wire when an ambient temperature is at or above a threshold temperature, thereby increasing the phase transformation temperature of the primary wire.

Abstract: The present invention provides a high-temperature shape memory alloy, in which Hf, Zr, Ta, Nb, V, Mo, and W as a third element except Ni are added to TiPd to thereby improve high-temperature strength and exhibit large shape recovery in a high-temperature range of 200° C. to 500° C., and a method for producing the high-temperature shape memory alloy.

Abstract: Articles made of shape memory alloys having improved fatigue performance and to methods of treating articles formed from shape memory alloy materials by pre-straining the articles (or desired portions of the articles) in a controlled manner so that the resultant articles exhibit improved fatigue performance. The shape memory articles are preferably medical devices, more preferably implantable medical devices. They are most preferably devices of nitinol shape memory alloy, most particularly that is superelastic at normal body temperature. The pre-straining method of the present invention as performed on such articles includes the controlled introduction of non-recoverable tensile strains greater than about 0.20% at the surface of a desired portion of a shape memory alloy article. Controlled pre-straining operations are performed on the shape-set nitinol metal to achieve non-recoverable tensile strain greater than about 0.20% at or near the surface of selected regions in the nitinol metal article.

Abstract: A method and an apparatus confer full superelastic properties to the active surface of a mechanical component constructed of a superelastic material prior to service. A compressive load is applied to the active surface of the mechanical component followed by removing the compressive load from the active surface whereby substantially all load strain is recoverable after applying and removing of subsequent compressive loads.

Abstract: A system and method for actively damping tension members modulates the natural frequency of shape memory alloys incorporated into tension members, such as suspension ropes or cables. The frequency of the tension member can be modulated by heating the shape memory alloy, such modulation preventing potentially destructive resonance with natural exciting forces.

Abstract: The invention discloses the internal structures and processes to synthesize the structure of self-healing materials, especially metallic materials, metal matrix micro and nanocomposites. Self-healing is imparted by incorporation of macro, micro or nanosize hollow reinforcements including nanotubes, filled with low melting healing material or incorporation of healing material in pockets within the metallic matrix; the healing material melts and fills the crack. In another concept, macro, micro and nanosize solid reinforcements including ceramic and metallic particles, and shape memory alloys are incorporated into alloy matrices, specially nanostructured alloy matrices, to impart self healing by applying compressive stresses on the crack or diffusing material into voids to fill them.

Abstract: We describe herein biocompatible single crystal Cu-based shape memory alloys (SMAs). In particular, we show biocompatibility based on MEM elution cell cytotoxicity, ISO intramuscular implant, and hemo-compatibility tests producing negative cytotoxic results. This biocompatibility may be attributed to the formation of a durable oxide surface layer analogous to the titanium oxide layer that inhibits body fluid reaction to titanium nickel alloys, and/or the non-existence of crystal domain boundaries may inhibit corrosive chemical attack. Methods for controlling the formation of the protective aluminum oxide layer are also described, as are devices including such biocompatible single crystal copper-based SMAs.