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.

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.

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.

Herein is provided a ferrous shape memory alloy (SMA) wire and processes for production of ferrous shape memory alloy wire that do not require crystallographic texturing processes to achieve superior superelastic and SMA wire properties. The shape memory alloy wire includes an elongated wire body with a longitudinal-axis length of iron alloy material and has a cross-sectional wire diameter that is less than about 1 millimeter. The iron alloy material has an oligocrystalline crystallographic morphology along the longitudinal-axis length. The iron alloy material has a ′-fcc crystallographic matrix and a volume fraction of ′-LH crystallographic precipitates in the ′-fee crystallographic matrix.

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.

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.

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.

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.

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.

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.