Related papers: NiTi shape-memory transformations: minimum-energy …
Nitinol (NiTi), the most widely used shape-memory alloy, exhibits an austenite phase that has yet to be identified. The usually assumed austenite structure is cubic B2, which has imaginary phonon modes, hence it is unstable. We suggest a…
Changes in temperature or stress state may induce reversible B2$\leftrightarrow$(R)$\leftrightarrow$ B19' martensitic transformations and associated shape memory effects in close-to-stoichiometric nickel-titanium (NiTi) alloys. Recent…
The work presents a thermomechanical model for polycrystalline NiTi-based shape memory alloys developed within the framework of generalized standard solids, which is able to cover loading-mode dependent localization of the martensitic…
The near equiatomic NiTi alloy is the most successful shape memory alloy by a large margin. It is widely and increasingly used in biomedical devices. Yet, despite having a repeatable superelastic effect and excellent shape-memory, NiTi is…
The martensitic transformation in NiTi-based Shape Memory Alloys (SMAs) provides a basis for shape memory effect and superelasticity, thereby enabling applications requiring solid-state actuation and large recoverable shape changes upon…
The shape memory behavior of a NiTi nanoparticle is analyzed by molecular dynamics simulations. After a detailed description of the equilibrium structures of the used model potential, the multi variant martensitic ground state, which…
Elastic and dissipative properties of a NiTi shape memory alloy have been studied in both the martensite and austenite phases, using the free-decay of a vibrating Nitinol wire. The influence of air was estimated from a martensite…
The identification and use of reversible Martensitic transformations, typically described as shape memory transformations, as a new class of solid-solid phase change material is experimentally demonstrated here for the first time. To prove…
Shape memory alloys like NiTi are at the core of emerging thermal management applications, including elastocaloric refrigeration, thermoelastic harvesting, and latent heat storage. Most of these applications benefit from a small scale due…
Nickel titanium (NiTi) is a protypical shape-memory alloy used in a range of biomedical and engineering devices, but direct molecular dynamics simulations of the martensitic B19' -> B2 phase transition driving its shape-memory behavior are…
Contactless, laser-based resonant ultrasound spectroscopy was utilized to monitor changes in elastic properties in single-crystalline NiTi shape memory alloy. It was observed that the elastic behavior of the temperature-induced B19$^\prime$…
The ability to control the stress-induced phase transformation of the shape memory alloy, NiTi, is an important technological challenge that must be understood for their wide application in devices that can exploit their reversible strain…
Shape-memory alloys exhibit a solid-to-solid phase transition that involves a temperature-driven rearrangement of their crystal structure and is responsible for their remarkable properties and numerous technological applications. Here, we…
Martensitic and magnetic properties of ferromagnetic shape memory alloys are known to depend up on structural modulations and associated changes in the Fermi surface. These modulations although periodic and spanning over multiple unit…
Needle-like twins are observed experimentally within the transition layer at the martensite-twinned martensite interface. We utilize a phase-field approach to investigate this microstructure. Our goal is to simulate the morphology of the…
Slow time-dependent fluctuations, or noise, in the electrical resistance of dc magnetron sputtered thin films of Nickel Titanium shape memory alloys have been measured. Even in equilibrium, the noise was several orders of magnitude larger…
Modulated martensites play an important role in magnetic shape memory alloys, because all functional properties are closely connected to the twin microstructure and the phase boundary. The nature of the modulated martensites is still…
In this paper we introduce a 3D phenomenological model for shape memory behavior, accounting for: martensite reorientation, asymmetric response of the material to tension/compression, different kinetics between forward and reverse phase…
The reverse martensitic ("austenitic") transformation upon heating of equiatomic nickel-titanium nanoparticles with diameters between 4 and 17 nm is analyzed by means of molecular-dynamics simulations with a semi-empirical model potential.…
Ni57.5Mn17.5Ga25 shape memory alloy exhibits a complex transformation behavior, appearing after aging. Aging in the austenitic state resulted in an ordinary decrease of the martensitic transformation temperature. Contrary to this, aging in…