Abstract: The present invention relates to a method of making clips which can be used to engage body tissue for the purpose of closing wounds. Such clips are generally annular in shape and have radially inwardly extending tines. The present invention first forms a precursor which, in one embodiment, has the tines extending radially outwardly from the annular body and then forms the clip by inverting the precursor such that the tines extend radially inwardly. In an alternate embodiment, the precursor is formed with an over-sized lateral dimension and then compressed inwardly to bring the tines closer together and to reduce the lateral dimension of the precursor. It is preferred to manufacture such clips from a superelastic alloy such as nickel-titanium, in which case the inverted or compressed precursor must be heated and quenched to heat set the clip in its final shape.

Abstract: In some embodiments, a variable stiffness structure is provided having constant stiffness material layers and variable modulus material layers arranged in alternating layers. The variable modulus material layers have a material with a changeable elastic modulus in response to an applied energy field so as to allow reversible coupling and decoupling of stress transfer between successive layers of the constant stiffness material layers to provide a change in a bending stiffness of the variable stiffness structure. The constant stiffness material layers may include segmented portions. The constant stiffness material layers may have segmented portions arranged such that successive layers of the plurality of constant stiffness material layers have overlapping segmented portions. The variable modulus material layers may have shaped structures, for example, corrugation, pillars, striations, tubular, or honeycomb configurations.

Abstract: The invention relates to a method for producing magnetically active shape memory metal alloy, said metal alloy containing nickel, manganese and gallium. In the method, the different components of the metal alloy are melted, and the melt is homogenized essentially at the melting temperature; the obtained metal alloy is cast, and the cast metal alloy is subjected to directional solidification at 10-100° C. below the liquidus temperature of said metal alloy.

Abstract: Devices and methods of making devices having one or more components made of single crystal shape memory alloy capable of large recoverable distortions, defined herein as “hyperelastic” SMA. Recoverable Strains are as large as 9 percent, and in special circumstances as large as 22 percent. Hyperelastic SMAs exhibit no creep or gradual change during repeated cycling because there are no crystal boundaries. Hyperelastic properties are inherent in the single crystal as formed: no cold work or special heat treatment is necessary. Alloy components are Cu—Al—X where X may be Ni, Fe, Co, Mn. Single crystals are pulled from melt as in the Stepanov method and quenched by rapid cooling to prevent selective precipitation of individual elemental components. Conventional methods of finishing are used: milling, turning, electro-discharge machining, abrasion. Fields of application include aerospace, military, automotive, medical devices, microelectronics, and consumer products.

Abstract: A method of characterizing phase transformations of a shape memory material specimen entails recording data from the specimen during heating and cooling. The temperature of the specimen is changed in a first direction to a first temperature sufficient to define a first inflection and a second inflection in the data being recorded. The temperature of the specimen is changed in a second direction to a second temperature sufficient to define a third inflection in the data. The third inflection is formed by overlapping primary and secondary sub-inflections. The temperature of the specimen is changed in the first direction to a third temperature sufficient to define the first inflection but not sufficient to define the second inflection. The temperature of the specimen is then changed in the second direction to a fourth temperature sufficient to define the secondary sub-inflection in the data being recorded.

Abstract: A method of forming a single crystal in a thin film by progressively rapidly heating (and cooling) a narrow band of amorphous material. The amorphous thin film may be of shape memory alloy such as TiNi or CuAlNi. Heating may be accomplished by a line-focused laser beam. The thin film may be formed by sputter deposition on a substrate such as silicon. The thin film crystal that is formed has non-isotropic stress/strain characteristics, and very large recoverable strain in a preferred direction. The single crystal SMA exhibits greater strain recovery; Constant force deflection; Wider transition temperature range; Very narrow loading hysteresis; and Recovery that is repeatable & complete. Single Crystal SMA is manufactured by pulling a single crystal from melt, a method similar to that used by the semiconductor industry to fabricate silicon boules. This process enables manufacture of materials that approach theoretical limits.

Abstract: A stent, to be implanted in a human body, is made of a super-elastic metal which is formed approximately cylindrically and integrally and which shows super-elasticity before and after said stent is inserted into said human body. The stent has a plurality of annular parts (expansion element) deformable in a direction in which an outer diameter thereof contracts, when a stress is applied thereto and a plurality of connection parts (connection element) each connecting said adjacent annular parts to each other, with said annular parts arranged in an axial direction of said stent. Each of said annular parts is elastically deformable owing to super-elasticity thereof, whereas each of said connection parts is substantially a plastically deformable part not super-elastic entirely or partly.

Abstract: A spring including a wire having an elasticity by which the wire is compressible by an external force to a first position at which first and second ends thereof of are separated by a first distance and when the force is removed or an electrical current applied, the wire is extensible in response to an internal spring force to a second position at which the wire is substantially straight. A spring assembly is disclosed including a plurality of inventive wires cross-coupled with a support structure consisting of a plurality of coaxial rings. In the assembly, the wires extend parallel to an axis through a center of the rings.

Abstract: A method of coating a pre-formed trainable material, such as nitinol wire, with a heat resistant substance, heat treating, and cooling to form a desired shape. The substance can be removed by various methods after heat treatment, depending upon the composition of the substance. The method includes forming a trainable material around a mold that dissolves, vaporizes, or can otherwise be removed. The method is useful for forming complicated shapes that would be expensive or impossible to form by conventional methods.

Abstract: A composite element comprises:(a) a metal or metal alloy component having an elastic modulus that decreases with increasing temperature in a temperature range; and (b) sufficient amount of a shape memory alloy component having an elastic modulus that shows an increase in elastic modulus with increasing temperature in the said temperature range, such that the elastic modulus of the composite element does not fall substantially as the temperature is increased across the said temperature range. An article comprising such a composite element is suitable for use in high temperature applications, including motor vehicle components.

Abstract: The present invention relates generally to a shape memory and/or super-elastic material, such as a nickel titanium alloy. Additionally or alternatively, the present invention relates to a super-elastic or pseudo-elastic material that has an initial transition temperature Af above a body temperature. The shape memory material can have a super-elasticity or pseudo-elasticity property at a temperature below the initial transition temperature Af of the material. For example, the shape memory material can have its workable temperature for producing super-elasticity or pseudo-elasticity of about 0° C. to 15° C. below the initial transition temperature Af. The shape memory material can be malleable at a room temperature, and become super-elastic or pseudo-elastic at a body temperature. In addition, the present invention relates to a method of making a shape memory or a super-elastic material.

Abstract: A process comprising the steps of providing a precursor for an implantable medical device, at least a portion of the precursor made of a shape memory material, the shape memory material having a receptacle for receiving a marker therein, the shape memory material having an austenitic and a martensitic phase; enlarging the receptacle while the shape memory material is in the martensitic phase; inserting a marker in the receptacle while the shape memory material is in the martensitic phase; and thereafter transforming the precursor to the austenitic phase.

Abstract: The present invention provides for Cu—Zn—Al(6%) alloy and an improved process to lower the martensitic transformation temperature, by a low temperature re-betatising treatment from 110° C. to 30° C. i.e. a lowering of 80° C. wherein previously high temperature betatised material has been subjected to re-betatising at lower temperature in order to utilize the material suitably.

Abstract: A medical device for use within a body lumen that is made from a binary nickel-titanium alloy that remains in its austenitic phase throughout its operational range is disclosed. The medical device, such as an intraluminal stent, is made from superelastic nickel-titanium and may optionally be alloyed with a ternary element. By adding the ternary element and/or through heat treatment, it is possible to lower the phase transformation temperature between the austenitic phase and the martensitic phase of the nickel-titanium alloy. By lowering the phase transformation temperature, the martensite deformation temperature is likewise depressed. It is possible then to depress the martensite deformation temperature below body temperature such that when the device is used in a body lumen for medical treatment, the nickel-titanium device remains completely in the austenitic phase without appearance of stress-induced martensite even if the device is placed under stress.

Abstract: A cardiac harness for treating congestive heart failure is disclosed. The harness applies elastic, compressive reinforcement on the left ventricle to reduce deleterious wall tension and to resist shape change of the ventricle during the mechanical cardiac cycle. Rather than imposing a dimension beyond which the heart cannot expand, the harness provides no hard limit over the range of diastolic expansion of the ventricle. Instead, the harness follows the contour of the heart throughout diastole and continuously exerts gentle resistance to stretch. Also disclosed is a method of delivering the cardiac harness to the heart minimally invasively.

Abstract: The manufacturing methods according to the present teachings provide shape memory alloy products having both a uniform composition and a precise shape memory recovery temperature. In this manufacturing method, raw material powders (e.g., Ti and Ni powders) may be precisely mixed. Next, a compound may be synthesized from the raw material powder mixture using a combustion synthesis method. The combustion synthesized compound may be melted and cast into a desired shape (e.g., a shape of the final product or a shape close to that of the final product).

Abstract: A super-elastic titanium alloy for medical use consisting essentially of: molybdenum (Mo) as a ? stabilizer element of titanium (Ti): from 2 to 12 at %; an ? stabilizer element of the titanium (Ti): from 0.1 to 14 at %; and the balance being titanium (Ti) and inevitable impurities. The ? stabilizer element is at least one element selected from the group consisting of aluminum (Al), gallium (Ga) and germanium (Ge).

Abstract: A self-healing tribological surface comprises a shape memory material. The self-healing tribological surface can be used for recovering a scratches and/or indentations in the surface. Processes for recovering scratches or indentations generally comprises forming a shape memory material onto the surface; scratching or indenting the surface; and heating an area about the scratch or indentation, wherein a depth of the scratch or the indentation decreases after heating as compared to the depth prior to heating.

Abstract: A process for making Type 60 Nitinol with shape memory effect from hot-worked material, such as hot rolled Type 60 Nitinol sheet or plate, includes heat treatment to a temperature of 600° C.–800° C. and holding the material at that temperature until the temperature has equalized throughout, and then heat soaking at that temperature for about 15 minutes. The material is then quenched immediately from that temperature, to a temperature below 300° C. This heat treatment produces Type 60 Nitinol in a condition denoted “ultraelastic”. Ultraelastic Type 60 Nitinol has a shape memory characteristic having a very low transition temperature. The transition temperature can be tailored within a wide temperature range by the temperature of the initial heat treatment and subsequent rate of cooling.

Abstract: A method of treating a shape memory alloy to improve its various characteristics and to cause it to exhibit a two-way shape memory effect. A raw shape memory alloy having a substantially uniformly fine-grained crystal structure is prepared and then its crystal orientations are arranged substantially in a direction suitable for an expected operational direction, such as tensile or twisting direction or the like, in which the shape memory alloy is expected to move when used in an actuator after the completion of the treatment.

Abstract: A method of attaching a first member of one of quartz and a ceramic to a metal member. The method includes creating a hole in the metal member, the hole being smaller in size than the size of the first member over a temperature range, heating the metal member to a temperature sufficient to expand the hole to allow insertion of the first member in the hole, inserting a portion of the first member into the hole, and cooling the metal member to form a joined structure of the first member and the metal member.

Abstract: A super-elastic titanium alloy for medical use consisting essentially of: a molybdenum (Mo) as a ? stabilizer element of titanium (Ti): from 2 to 12 at %; an ? stabilizer element of the titanium (Ti): from 0.1 to 14 at %; and the balance being titanium (Ti) and inevitable impurities. The ? stabilizer element is at least one element selected from the group consisting of aluminum (Al), gallium (Ga) and germanium (Ge).

Abstract: Guide wires and catheters made from a functionally graded alloy comprising 3-10 weight % Al and 5-20 weight % Mn, the balance being substantially Cu and inevitable impurities. The functionally graded alloy is produced by forming the copper-based alloy, maintaining it at a temperature of at least 500° C. and rapidly cooling it, and then subjecting the alloy to an aging treatment by a gradient temperature heater.

Abstract: In a joining method for a frame of spectacles, and in more particular to a method for joining a bridge or a temple to a lens rim, a joining method for a frame of spectacles comprises deforming a joining portion of a member made of a shape memory alloy material so as to be insertable into a pipe for joining the member to a lens rim, and joining the joining portion of the member to the pipe by returning the joining portion of the member to an original shape before the deformation after the member is inserted into the pipe.

Abstract: A conductive hinge is made of a superelastic shape memory alloy such as nitinol (NiTi) having a large elastic strain limit for enabling the hinge to bend to a small radius during stowage and flexible return to a trained rigid hinge position by training the shape memory alloy to assume a predetermined deployed configuration when released from a stowage configuration. The hinge is trained by forging at a temperature above a training temperature. The hinge is stowed and released in the superelastic state to deploy solar cell panels as the hinges unfold to the trained deployed configuration.

Abstract: A method of generating force between a structure and an additional member, particularly for reinforcing an existing structure so that an additional member can share existing load. Pre-cooled or pre-heated shims of shape memory alloy (SMA) are inserted between the additional member and the existing structure, or between different sub-units of the additional member, or between the additional member and shoes fixed for this purpose to the existing structure. On subsequent warming or cooling the SMA shims expand to apply compressive forces to the portions of the structure, additional member or shoe(s) with which they are in contact on their opposite sides. Further compressive, tensile, flexural or torsional forces will be developed within other parts of the structure and additional member as a result of the shim expansion depending on the particular arrangement.

Abstract: A NbC-added Fe—Mn—Si-based shape memory alloy is provided, showing a shape memory property even if a special treatment such as training is not performed. A Fe—Mn—Si-based shape memory alloy containing Nb and C is rolled by 10 to 30% in a temperature range of 500 to 800° C. under austenite condition, then, subjected to an aging treatment by heating in a temperature range of 400 to 1000° C. for 1 minute to 2 hours.

Abstract: Nickel-titanium alloys that have been deep drawn in a cold working process have linear pseudoelastic behavior without a phase transformation or onset of stress-induced martensite. A medical device made from a structural element which has been deep drawn and subsequently formed into a desired medical device geometry will experience such linear pseudoelastic behavior.

Abstract: Iron-manganese-silicon-based shape memory alloys comprising:

Abstract: The manufacturing methods according to the present teachings provide shape memory alloy products having both a uniform composition and a precise shape memory recovery temperature. In this manufacturing method, raw material powders (e.g., Ti and Ni powders) may be precisely mixed. Next, a compound may be synthesized from the raw material powder mixture using a combustion synthesis method. The combustion synthesized compound may be melted and cast into a desired shape (e.g., a shape of the final product or a shape close to that of the final product).

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 nonrecoverable tensile strain greater than about 0.20% at or near the surface of selected regions in the nitinol metal article.

Abstract: A self-healing tribological surface comprises a shape memory material. The self-healing tribological surface can be used for recovering a scratches and/or indentations in the surface. Processes for recovering scratches or indentations generally comprises forming a shape memory material onto the surface; scratching or indenting the surface; and heating an area about the scratch or indentation, wherein a depth of the scratch or the indentation decreases after heating as compared to the depth prior to heating.

Abstract: High-strength, low-hysteresis TiNi-based shape-memory alloys (SMAS) employing fully coherent low-misfit nanoscale precipitates, wherein the precipitate phase is based on an optimized composition for high parent-phase strength and martensite phase stability, and compensating the stored elastic energy through the addition of martensite stabilizers. The alloys, with a yield strength in excess of 1200 MPa, are useful for applications such as self-expanding stents, automotive actuators, and other applications wherein SMAs with high output force and long cyclic life are desired.

Abstract: A method of coating a pre-formed trainable material, such as nitinol wire, with a heat resistant substance, heat treating, and cooling to form a desired shape. The substance can be removed by various methods after heat treatment, depending upon the composition of the substance. The method includes forming a trainable material around a mold that dissolves, vaporizes, or can otherwise be removed. The method is useful for forming complicated shapes that would be expensive or impossible to form by conventional methods.

Abstract: To remarkably improve shape-memory properties without the need for strictly controlling the composition, the present invention provides a Ti—Ni-based shape-memory alloy having a titanium content within a range of from 50 to 55 atomic %, which comprises an amorphous alloy heat-treated at a temperature of from 600 to 800 K, in which subnanometric precipitates generating coherent elastic strains are formed and distributed in the bcc parent phase(B2).

Abstract: Methods of fabricating a free standing thin film of shape memory alloy material, and products made by the methods. A sacrificial layer of a metallic material is deposited onto the surface of a substrate. Then an amorphous shape memory alloy is sputter deposited onto the outer surface of the sacrificial layer. The sacrificial layer is etched away, leaving the thin film free standing, that is separated from the substrate. The thin film is annealed by heating into a crystalline state, with the annealing step carried out either after the film has been separated from the substrate, or while remaining attached to it.

Abstract: A process for making Type 60 Nitinol with shape memory effect from hot-worked material, such as hot rolled Type 60 Nitinol sheet or plate, includes heat treatment to a temperature of 600° C.-800° C. and holding the material at that temperature until the temperature has equalized throughout, and then heat soaking at that temperature for about 15 minutes. The material is then quenched immediately from that temperature, to a temperature below 300° C. This heat treatment produces Type 60 Nitinol in a condition denoted “ultraelastic”. Ultraelastic Type 60 Nitinol has a shape memory characteristic having a very low transition temperature. The transition temperature can be tailored within a wide temperature range by the temperature of the initial heat treatment and subsequent rate of cooling.

Abstract: A method for producing a non-welded shape memory alloy ring, such as Nitinol, includes a wire segment. The alloy ring may be used in a venting mechanism for rocket motors or as a coupling device, such as for fitting piping.

Abstract: The present invention employs a shape memory alloy that exhibits a two-way shape memory effect and that has a stress-strain property that, in a stress-strain diagram, the stress-strain curve comprises a gentler gradient portion extending with relatively small gradients and a steeper gradient portion extending with relatively great gradients. The shape memory alloy is operated in the region surrounded by the gentler gradient portion, the steeper gradient portion, a practical stress limit line, a straight line connecting the intersection of the practical stress limit line and a strain limit line near shape recovery completion on which the strain of the shape memory alloy reaches a specified value in a state close to the shape recovery completion and the point where the strain is zero at a low temperature in the stress-strain diagram.

Abstract: An improved guiding member for use within a body lumen having a unique combination of superelastic characteristics. The superelastic alloy material has a composition consisting of about 30% to about 52% (atomic) titanium, and about 38% to 52% nickel and may have one or more elements selected from the group consisting of iron, cobalt, platinum, palladium, vanadium, copper, zirconium, hafnium and niobium. The alloy material is subjected to thermomechanical processing which includes a final cold working of about 10 to about 75% and then a heat treatment at a temperature between about 4500° and about 600° C. and preferably about 4750° to about 5500° C. Before the heat treatment the cold worked alloy material is preferably subjected to mechanical straightening. The alloy material is preferably subjected to stresses equal to about 5 to about 50% of the room temperature ultimate yield stress of the material during the thermal treatment.

Abstract: A piece of jewelry (10) is disclosed, comprising first and second substantially opposing end portions (14, 16), at least one said end potion being moveable from an open state A in which said end portions (14, 16) are spaced apart towards a closed state B in which said end portions (14, 16) are spaced apart by, a reduced gap or are substantially engaged. The piece of jewelry (10) comprises at least a section (12a) made from a shape memory material and said shape memory material is adapted, at or above a predetermined temperature Ta, to bring said end portions (14, 16) towards each other. This occurs preferably when said shape memory material is placed in the region of a body part of a wearer such that shape memory effect is used in co-operation with body temperature to fit said piece of jewelry to its wearer whist simultaneously causing, a change in externally visible shape or configuration or the jewelry.

Abstract: Impact resistant components and methods of protecting structures from impacts. The components are interposed between a potential point of impact and a structure to be protected. They comprise a shape memory alloy (SMA) exhibiting pseudoelastic behavior, and having a high strain to failure.

Abstract: This invention relates to a process for manufacturing, shaping, and machining of a part made of a shape memory alloy, comprising a single step in which the said part is fabricated, shaped and machined simultaneously in a single operation by a cutting machining process such as turning. The invention is also related to the part prepared by this process, which is particularly a helical spring with adjacent turns. In particular, this part may be used in actuator or actuator/sensor type devices.

Abstract: The invention concerns a method whereby at least a predefined zone (A) of the object (2) is irradiated with a laser beam (4) capable of heating said zone sufficiently, to a temperature less than the material melting point, to provoke a change in the microstructure (for example crystallisation or recrystallisation) of said zone, said zone being heated at a temperature and for a time interval not rendering the material amorphous. The invention is applicable for example to reversible actuators and grippers.

Abstract: A method of fabricating ternary TiNi-based alloys to achieve substantially higher phase-change transition temperatures in the resulting SMA materials and which have optimal thermo-mechanical properties. One target is provided which comprises the element Ti, a second target comprises the element Ni and a third target comprises an element which when combined with Ti and Ni can produce a shape memory alloy. The three targets are co-sputtered onto a substrate at rates which are controlled so that the sum of the percentage composition of the elements that are from the left side of the periodic table are substantially 50 atomic percent, and the sum of percentage composition of the elements that are from the right side of the periodic table comprise the remaining 50 atomic percent.

Abstract: Nickel-titanium alloys that have been deep drawn in a cold working process have linear pseudoelastic behavior without a phase transformation or onset of stress-induced martensite. A medical device made from a structural element which has been deep drawn and subsequently formed into a desired medical device geometry will experience such linear pseudoelastic behavior.

Abstract: A super-elastic titanium alloy for medical use consisting essentially of:

Abstract: A medical device for use within a body lumen that is made from a binary nickel-titanium alloy that remains in its austenitic phase throughout its operational range is disclosed. The medical device, such as an intraluminal stent, is made from superelastic nickel-titanium and may optionally be alloyed with a ternary element. By adding the ternary element and/or through heat treatment, it is possible to lower the phase transformation temperature between the austenitic phase and the martensitic phase of the nickel-titanium alloy. By lowering the phase transformation temperature, the martensite deformation temperature is likewise depressed. It is possible then to depress the martensite deformation temperature below body temperature such that when the device is used in a body lumen for medical treatment, the nickel-titanium device remains completely in the austenitic phase without appearance of stress-induced martensite even if the device is placed under stress.

Abstract: A conformable catheter comprising a catheter handle, an elongated catheter tube, and a distal tip portion of the catheter tube, capable of assuming a desired pre-programmed shape. A wire member is disposed within the core of the catheter's tip portion and is formed of a material, such as, for example, a shape-memory binary nickel-titanium alloy, that will assume a pre-programmed shape after pre-shaping, heat treatment, cooling and subsequent heating. To pre-program the shape of the wire member, prior to assembly of the catheter, the wire member is wound around a shaped, heat resistant fixture, heated until the temperature of the wire member exceeds the temperature at which the shape of the wire member on the fixture becomes programmed into the wire member, and cooled.

Abstract: To remarkably improve shape-memory properties without the need for strictly controlling the composition, the present invention provides a Ti—Ni-based shape-memory alloy having a titanium content within a range of from 50 to 55 atomic %, which comprises an amorphous alloy heat-treated at a temperature of from 600 to 800 K, in which subnanometric precipitates generating coherent elastic strains are formed and distributed in the bcc parent phase(B2).