In order to describe the deformation properties due to the martensitic transformation and the R-phase transformation of TiNi shape memory alloy, a thermomechanical constitutive equation considering the volume fractions of induced phases associated with both transformations is developed. The proposed constitutive equation expresses well the properties of the shape memory effect, pseudoelasticity...

The mechanical and magnetic properties of Ni-Mn-Sb intermetallic compounds are closely related to the martensitic transformation and martensite variant organization. However, studies of these issues are very limited. Thus, a thorough crystallographic investigation of the martensitic transformation orientation relationship (OR), the transformation deformation and their impact on the variant orga...

We have investigated the effect of pressure and thermal ageing on transformation behavior of Ni-%45.16Ti shape memory alloy. 70-320 MPa pressure was applied and annealed at 500 o C for 2 hour to see the effect of applied pressure on transformation temperature. It was observed that the starting and final temperature of austenit increased, the martensite start temperature almost remain constant a...

In this study, NiTi thin films were deposited on the glass and NaCl substrates by means of magnetron sputtering method. The influence of aging temperature, over the range 300-500 oC, on phase transformation and mechanical properties of the sputtered NiTi thin films were studied by differential scanning calorimetry (DSC) and nano-indentation assay, respectively. The DSC curves showed that the ag...

recently determined LVl~ to be 111918 J mol-I at temperatures below 1000 K, and pointed out that their experimental data were free from various 'intercept effects' which had dogged earlier investigations. Similarly, for T<1000K, they deduced '\~s=51.44Jmol-IK-I. There seem to be no data on the variation of LVl~ or ,\~s as a function of x. However, Lobo and Geigerl found that LVll: and ,\S~S do ...

Suzhi Li,1 Xiangdong Ding,1,2,*,† Ju Li,1,3,*,‡ Xiaobing Ren,1,4 Jun Sun,1 Evan Ma,1,5,*,§ and Turab Lookman2 1State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China 2Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA 3Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia,...

The most efficient way to tune microstructures and mechanical properties of metallic alloys lies in designing and using athermal phase transformations. Examples are shape memory alloys and high strength steels, which together stand for 1,500 million tons annual production. In these materials, martensite formation and mechanical twinning are tuned via composition adjustment for realizing complex...

" Thermomechanical behavior at the nanoscale and size effects in shape memory alloys. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Shape memory alloys (SMA) und...

The effect of amount of deformation on the martensitic transformation and shape memory effect in a Fe-16Mn-5Si-9Cr-4Ni alloy is studied. It is found that both 6and a'martensite are induced by deformation. With increasing amount of deformation, y+~-nx' transformation is greatly enhanced. the highest shape memory strain 3 3% is reached when the amount of deformation is about 5%.

Data about an effect of cyclic γ-α-γ martensitic transformations on the structure state of reverted austenite Fe-31.7 wt.% Ni-0.06 wt.% C alloy are presented. The effect of multiple direct γ-α and reverse α-γ martensitic transformations on fragmentation of austenitic grains has been investigated by electron microscopy and X-ray diffraction methods. An ultrafine structure has been formed by nano...