Porous NiTi alloys has a series of unique properties such as shape memory effect, superelastic behavior and energy absorbability that make them usable in a wide range of medical and industrial appliances. But the more probability of Ni release from a porous NiTi compare to the nonporous one has restricted it’s uses in implants. In the present research for resolving the problem, performing a cal...

Nitinol (NiTi), the most widely used shape-memory alloy, exhibits an austenite phase that has yet to be identified. The usually assumed austenitic structure is cubic B2, which has imaginary phonon modes, hence it is unstable. We suggest a stable austenitic structure that " on average " has B2 symmetry (observed by x-ray and neutron diffraction), but it exhibits finite atomic displacements from ...

The effect of superposed transitions in actuators with layered shape memory alloy (SMA) films undergoing martensitic phase transformation is analyzed in terms of a model developed for two layers of different composition, deposited at the same temperature on a substrate. A significant difference is observed in the actuation versus temperature relationship, depending on the thermal and elastic pr...

Laser annealing of shape memory alloy thin films provides new opportunities in actuator design and fabrication for microelectromechanical systems applications. In this paper, we present a three-dimensional thermal model to simulate the crystallization process when a laser beam is swept across an amorphous NiTi thin film. Experimental crystallite nucleation and growth rates are included in the m...

Abstract In this work, the corrosion behavior of bare nitinol (NiTi) alloy in Ringer's solution containing different concentrations sodium bis(2-ethylhexyl) sulfosuccinate (AOT) was first studied order to determine whether surfactant acts as a inhibitor. Results potentiostatic and potentiodynamic experiments allowed concluding that AOT is pitting inhibitor for NiTi. second stage research NiTi t...

Reza Mirzaeifar, Ken Gall, Ting Zhu, Arash Yavari, and Reginald DesRoches George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332,...

The temperature dependence of the crystallite nucleation and growth rates is measured for amorphous NiTi thin films. Using transmission electron microscopy, crystallites are shown to nucleate homogeneously in the film and to grow in a channeling mode. A mechanism that suppresses heterogeneous nucleation is proposed. By manipulating nucleation and growth rates, grains as large as 60 lm can be ob...

OBJECTIVES This study aimed to evaluate the safety and efficacy of a new nickel-titanium shape memory alloy compression anastomosis ring, NiTi CAR 27, in constructing an anastomosis for colorectal cancer resection compared with conventional staples. METHODS In total, 234 consecutive patients diagnosed with colorectal cancer receiving sigmoidectomy and anterior resection for end-to-end anastom...

BACKGROUND Orthodontic wires are the corner stones of the science and art of orthodontics and they remain in the patient's mouth for a prolonged period of 18-24 months. It is but natural to expect that they will undergo some biodegradation when in the oral environment during that period. This study aims to compare the biodegradation characteristics of four different orthodontic wires, stainless...