Reversibility of phase transformation, a basic requirement for functional properties shape memory alloys, such as superelasticity, is severely affected by plastic deformation. Here, strain glass has been utilized to improve the reversibility transformation. The incorporation Al into Ti-Zr-Ni-Cu induces and endows alloy with reversible transformation thus ideal superelasticity. In situ x-ray dif...

the phase transformation phenomenon due to the crystallographic change of shape memory alloys subjected to mechanical or thermal loading is very complicated. regarding the thermo-mechanical coupling effects in shape memory alloys, in case of high  loading rates, heat generation/absorption during the forward/reverse transformation, will lead in temperature-dependent variation and consequently af...

The aim of this work is to describe and compare mechanical properties of eight widely used nickel-titanium orthodontic wires under uniform testing conditions and to determine the influence of the heat treatments on the loss of the superelasticity. Ten archwires from two batches from eight different manufacturers were evaluated. A three-point bending test was performed, in accordance with ISO 15...

A superelasticity (shape memory) behavior has been discovered for the superlattice-structured ZnO nanohelices. By in situ manipulation using a nanoprobe, the nanohelix could elastically recover its shape after an extremely large axial stretching to a degree close to the theoretical limit, while suffering little residual plastic deformation. As a result, its spring constant can be increased cont...

This paper presents a constitutive model for shape-memory alloys that builds on ideas generated from recent micromechanical studies of the underlying microstructure. The presentation here is in one dimension. It is applicable in a wide temperature range that covers both the shape-memory effect and superelasticity, is valid for a wide range of strain rates and incorporates plasticity. The thermo...