Modeling of Deformation and Functional Properties of Shape Memory Alloys Based on a Microstructural Approach

2015 ◽  
Vol 81-82 ◽  
pp. 20-37 ◽  
Author(s):  
Aleksandr E. Volkov ◽  
Margarita E. Evard ◽  
Fedor S. Belyaev
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Functional Properties

A Comparative Study of Structure Formation in Thermomechanically Treated Ti-Ni and Ti-Nb-(Zr, Ta) SMA

2012 ◽  
Vol 706-709 ◽  
pp. 1931-1936 ◽  
Author(s):  
Sergey Prokoshkin ◽  
Vladimir Brailovski ◽  
Karine Inaekyan ◽  
Andrey Korotitskiy ◽  
Sergey Dubinskiy ◽  
...  
Keyword(s):  
Cold Rolling ◽  
Comparative Study ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Structure Formation ◽  
Thermomechanical Treatment ◽  
Functional Properties ◽  
Nanocrystalline Structure ◽  
Technological Factors

The processes of structure formation in Ti-Ni and in Ti-Nb-Zr, Ti-Nb-Ta shape memory alloys (SMA) under thermomechanical treatment (TMT) were studied. The TMT comprised cold rolling with true strains from e=0.25 to 2 and post-deformation annealing. Differences in these processes between two groups of alloys are considered. The main conclusions are as follows: nanostructures created by TMT are useful for radical improvement of the SMA functional properties, and an optimum nanostructure (nanocrystalline structure, nanosubgrained structure or theirmixture) should be selected by taking into account other structural and technological factors.

Creation of submicrocrystalline structure and improvement of functional properties of shape memory alloys of the Ti-Ni-Fe system with the help of ECAP

2007 ◽  
Vol 49 (1-2) ◽  
pp. 51-56 ◽  
Author(s):  
S. D. Prokoshkin ◽  
M. N. Belousov ◽  
V. Ya. Abramov ◽  
A. V. Korotitskii ◽  
S. Yu. Makushev ◽  
...  
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Functional Properties ◽  
Submicrocrystalline Structure

Coherency strains of H-phase precipitates and their influence on functional properties of nickel-titanium-hafnium shape memory alloys

2018 ◽  
Vol 147 ◽  
pp. 83-87 ◽  
Author(s):  
Behnam Amin-Ahmadi ◽  
Joseph G. Pauza ◽  
Ali Shamimi ◽  
Tom W. Duerig ◽  
Ronald D. Noebe ◽  
...  
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Functional Properties ◽  
Nickel Titanium ◽  
Coherency Strains

Effect of the quasi-continuous equal-channel angular pressing on the structure and functional properties of Ti–Ni-based shape-memory alloys

2017 ◽  
Vol 118 (3) ◽  
pp. 279-287 ◽  
Author(s):  
I. Yu. Khmelevskaya ◽  
R. D. Karelin ◽  
S. D. Prokoshkin ◽  
V. A. Andreev ◽  
V. S. Yusupov ◽  
...  
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Equal Channel Angular Pressing ◽  
Functional Properties ◽  
Angular Pressing

Preparation by Twin Roll Casting and Characterization of TiNi Shape Memory Alloys Strips

2007 ◽  
Vol 130 ◽  
pp. 121-126 ◽  
Author(s):  
Richard Portier ◽  
Philippe Vermaut ◽  
Patrick Ochin ◽  
Tomasz Goryczka ◽  
Jorge Malarría
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Functional Properties ◽  
Plane Surface ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
High Transformation ◽  
Production Technologies ◽  
Twin Roll

The thermoelastic martensitic transformation which gives remarkable functional properties to Shape Memory Alloys (SMA) is very sensitive to the chemistry of the alloys and to its microstructure. In many cases, especially for alloys with high transformation temperatures, applications are limited by the poor ductility. To overcome the brittleness of SMA, one approach can be effective : the development of non conventional production technologies which enable to obtain materials in forms close to requirements: strips of SMA have been prepared by Twin Roll Casting (TRC). The formation of a solid sheet with plane surface is only possible for a limited combination of the different machine parameters and they will be discussed. For comprehension of the process parameters effect, the attention will be focused on TiNi. Microstructures and functional properties will be examined in relation with the microstructures induced by the technique or after specific thermal treatment.

Functional Properties of Ti-Ni-Based Shape Memory Alloys

2008 ◽  
Vol 59 ◽  
pp. 156-161 ◽  
Author(s):  
I. Khmelevskaya ◽  
Sergey Prokoshkin ◽  
Vladimir Brailovski ◽  
K.E. Inaekyan ◽  
Vincent Demers ◽  
...  
Keyword(s):  
Grain Size ◽  
Cold Rolling ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Functional Properties ◽  
High Pressure Torsion ◽  
Martensitic Transformations ◽  
Critical Temperatures ◽  
Recoverable Strain ◽  
Ultrafine Grained

The main functional properties (FP) of Ti-Ni Shape Memory Alloys (SMA) are their critical temperatures of martensitic transformations, their maximum completely recoverable strain (er,1 max) and maximum recovery stress (sr max). Control of the Ti-Ni-based SMA FP develops by forming well-developed dislocation substructures or ultrafine-grained structures using various modes of thermomechanical treatment (TMT), including severe plastic deformation (SPD). The present work shows that TMT, including SPD, under conditions of high pressure torsion (HPT), equal-channel angular pressing (ECAP) or severe cold rolling followed by post-deformation annealing (PDA), which creates nanocrystalline or submicrocrystalline structures, is more beneficial from SMA FP point of view than does traditional TMT creating well-developed dislocation substructure. ECAP and low-temperature TMT by cold rolling followed by PDA allows formation of submicrocrystalline or nanocrystalline structures with grain size from 20 to 300 nm in bulk, and long-size samples of Ti-50.0; 50.6; 50.7%Ni and Ti-47%Ni-3%Fe alloys. The best combination of FP: sr max =1400 MPa and er,1 max=8%, is reached in Ti-Ni SMA after LTMT with e=1.9 followed by annealing at 400°C which results in nanocrystalline (grain size of 50 to 80 nm) structure formation. Application of ultrafine-grained SMA results in decrease in metal consumption for various medical implants and devices based on shape memory and superelastiсity effects.

Sign in / Sign up

Export Citation Format

Share Document