The present article is aimed at studying the deformation behavior of TiNi wire and knitted metal mesh under uniaxial tension revealing role geometry on their main mechanical characteristics mechanisms behavior. temperature dependence curve electrical resistance indicates that a two-stage martensitic transformation B2→R→B19′ occurring, responsible for superelasticity effect. TEM results showed r...

A recently developed crystal-mechanics-based constitutive model for polycrystalline shape-memory alloys (Thamburaja and Anand [1]) is shown to quantitatively predict the in-plane anisotropy of superelastic sheet Ti-Ni to reasonable accord. Keywords— Phase transformations, Constitutive equations, Finite-elements, Mechanical testing.

Porous NiTi alloys were prepared by microwave sintering using ammonium hydrogen carbonate (NH4HCO3) as the space holder agent to adjust the porosity in the range of 22-62%. The effects of porosities on the microstructure, hardness, compressive strength, bending strength, elastic modulus, phase transformation temperature and superelasticity of the porous NiTi alloys were investigated. The result...

The hysteresis that occurs during superelasticity caused by the stress-induced first-order martensite transformation is sometimes detrimental to properties of superelastic materials. In this paper, first-principles calculations are performed systematically investigate effects chemical composition and crystal disorder on Ni50-xCoxM25Ga25 (M = Mn, Fe) Heusler alloys. Calculations stress-strain re...

In this study, the combined effects of strengthening, precipitates, and textures on the shape recovery ability and superelasticity of thermomechanically treated Ti49.3Ni50.7 shape memory alloy (SMA) in both the rolling and transverse directions were studied by experimental measurements and theoretical calculations. Experimental results and theoretical calculations showed that the 300 °C × 100 h...

The superelastic effect in shape memory alloys (SMAs) is attributed to the stressinduced reversible austenitic-martensitic phase transformations. It is characterized by the development of significant strains which are fully recoverable upon unloading, and also characterized by the stress-hysteresis in the loading and unloading cycle which corresponds to the energy dissipated during phase transf...

A structural model of carbon nanocoils (CNCs) on the basis of carbon nanotubes (CNTs) was proposed. The Young's moduli and spring constants of CNCs were computed and compared with those of CNTs. Upon elongation and compression, CNCs exhibit superelastic properties that are manifested by the nearly invariant average bond lengths and the large maximum elastic strain limit. Analysis of bond angle ...

Nitinol (Nickel-Titanium) alloys exhibit a combination of properties which make these alloys particularly suited for self-expanding stents. Some of these properties cannot be found in engineering materials used for stents today. The paper describes the fundamental mechanism of shape memory and superelasticity. Material properties and device characteristics like elastic deployment, thermal deplo...