Abstract:
A novel shape memory alloy of FenullMnnullSi system containing at least Fe, Mn, and Si wherein the alloy contains niobium carbide in the structure and is improved in that a sufficiently satisfactory shape memory effect is provided without carrying out a special treatment termed training.
Abstract:
In order to provide a pipe joint of stainless steel including more than 10% of Cr which joint has excellent shape memory effect, the stainless steel comprises up to 0.10% of C, 3.0 to 6.0% of Si, 6.0 to 25.0% of Mn, up to 7.0% of Ni, more than 10.0 to 17.0% of Cr, 0.02 to 0.30% of N, 2.0 to 10.0% of Co, and optionally one or more selected from 0.05 to 0.8% of Nb, 0.05 to 0.8% of V, 0.05 to 0.8% of Zr, 0.05 to 0.8% of Ti, up to 2.0% of Mo and up to 2.0% of Cu and the alloying components are balanced so that no .delta.-ferritic phase may substantially appear in the annealed condition. Since the joint is treated so that it has such a shape memory effect that it will recover the memorized original shape with a smaller diameter when heated to an appropriate temperature, it can fasten a pipe or pipes merely by heating. Furthermore, the joint is galvanized on its surface so as to improve sealability in fastening the pipe(s) and to suppress crevice corrosion from occurring at the interface between the joint and pipe(s).
Abstract:
Thermally configurable structural elements (e.g., aircraft components such as an aircraft winglet spar) capable of assuming at least first and second structural configurations are provided whereby the structural element includes an integral actuation mechanism may be formed of sintered shape memory alloy (SMA) particles and sintered non-SMA particles formed by an additive layer manufacturing (ALM) process, such as 3D printing. The ALM process thereby provides by at least one thermally configurable region, and at least one non-thermally configurable region which is unitarily contiguous with the at least one thermally configurable region. The at least one thermally configurable region is capable of assuming at least first and second positional orientations in response to the presence or absence of a thermal input to thereby cause the structural element to assume the at least first and second structural configurations, respectively.
Abstract:
Methods for controlling properties of structural elements of implantable medical devices, where the structural elements contain shape memory alloys (SMAs) include promoting or inhibiting in vivo formation of R-phase crystal structure or converging or separating the R-phase from the austenite phase.
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:
Medical instruments, particularly, endodontic instruments with unique limited memory characteristics, and methods for making such instruments. One embodiment includes heat treating a finished endodontic instrument. A related embodiment includes electropolishing a finished endodontic instrument and then heat treating the endodontic instrument.
Abstract:
Anchoring system is appropriate for solid rock and concrete (2) and any firm bearing system. The anchor rod (4) of for example a threaded bar out of a shape memory alloy (SMA) is held in the armature bore (3) with a filling compound (5) as anchoring means. For filling the achoring bore (3) between anchor rod (4) and wall of the armature bore (3) a heat resistant filling compound (5) of a polymer connection on a two-component-basis or such on a cementous basis is used. Then the anchor rod (4) is heated by heat input over its butt that is emerging the filling compound on its austenit phase, which pre tensions the anchor rod (4). Finally, after the cooling of the filling compound (5) the anchor rod (4) is cooling of to ambient temperature. A counter bearing board (10) lays on the outer wall (1) around the port of the armature bore (3) and is tensed up with the anchor rod (4).
Abstract:
Ti—Nb—Hf/Zr—(Cr) alloy shape-memory wires are provided which are suitable for use in medical devices and actuators, and methods for manufacturing such wires are provided. The present shape-memory Ti—Nb—Hf/Zr—(Cr) alloy is a superelastic wire material particularly suited for in vivo applications. For example, the present Ti—Nb—Hf/Zr—(Cr) alloy wire is radiopaque, thereby enabling surgical use of a monolithic, shape-memory alloy wire while preserving the ability to monitor the in vivo location of the wire through X-ray or other radiation-based imaging systems. In addition, the present Ti—Nb—Hf/Zr—(Cr) alloy can be manufactured to exhibit shape-memory alloy material properties without the use of nickel as an alloy constituent, thereby accommodating nickel-sensitive patients. The present Ti—Nb—Hf/Zr—(Cr) alloy can also be processed to exhibit a martensite/austenite transformation temperature near body-temperature, i.e., 37° C., so that shape-memory effects can be utilized to accomplish work in vivo.
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 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.