Effect of sintering methods and cobalt addition on the shape memory properties of porous TiNi-based alloy

The changes of shape memory characteristics and properties of the porous sintered TiNi-based alloy are possible by a choice of the sintering methods or use of cobalt doping additive, as the present investigation has showed. The comparative analysis of the temperature dependences of electric resistance and macrodeformation both alloys, obtained by reaction and diffusion sintering was conducted. Diffusion-sintered alloy have showed high shape memory parameters and a more uniform passing of martensitic transformations. This is connected with a larger fraction of TiNi phase (about 90 vol.%) after diffusion sintering. It was found that the martensitic transformation characteristics and reversibility of martensitic strain in the porous nickelid titanium depend on level of intrinsic stresses in the TiNi phase and stresses caused by Co impurity. The addition to 1.0 at.% Co decreases the internal stresses in the TiNi phase, and more than 1.0 at.% Co increases their due to the effect of precipitation hardening of the alloy.

Download Full-text

Effect Of Cobalt Addition On Shape Memory Effects In Porous TiNi - Based Alloys Obtained By Reaction And Diffusion Sintering

Advanced Materials Letters ◽

10.5185/amlett.2016.6043 ◽

2016 ◽

Vol 7 (8) ◽

pp. 630-634 ◽

Cited By ~ 4

Author(s):

Yasenchuk Yu. F.

Keyword(s):

Shape Memory ◽

Memory Effects ◽

Shape Memory Effects ◽

And Diffusion ◽

Diffusion Sintering ◽

Cobalt Addition ◽

Reaction And Diffusion

Download Full-text

On the effect of cobalt doping on thermoelastic martensitic transformations in ferromagnetic Heusler Ni50 − x Co x Mn29Ga21 magnetically controlled shape memory alloys

Technical Physics Letters ◽

10.1134/s1063785013080233 ◽

2013 ◽

Vol 39 (8) ◽

pp. 737-740 ◽

Cited By ~ 2

Author(s):

V. G. Pushin ◽

A. V. Korolev ◽

N. I. Kourov ◽

N. N. Kuranova ◽

E. B. Marchenkova ◽

...

Keyword(s):

Shape Memory Alloys ◽

Shape Memory ◽

Martensitic Transformations ◽

Cobalt Doping ◽

Thermoelastic Martensitic Transformations

Download Full-text

Defects and Diffusion in a Prototype of Shape Memory Alloys: β2' Au-Cd Alloys

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.283-286.139 ◽

2009 ◽

Vol 283-286 ◽

pp. 139-148

Author(s):

Devendra Gupta ◽

David S. Lieberman

Keyword(s):

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Thermal History ◽

Alloy Composition ◽

Martensitic Transformations ◽

Contributing Factors ◽

Diffusion Mechanisms ◽

And Diffusion ◽

Nanometer Regime

The Au-Cd alloys continue to be important vehicles of research for the shape memory effect involving martensitic transformations and related phenomena.They transform to a variety of martensitic structures depending on the alloy composition and thermal history. Additionally, the Au-rich alloys display rubber like behavior involving thermo-elastic memory. Defects and diffusion play important roles in determining these properties. Defects and diffusion mechanisms in the Au- 47.5 - 50.5 at.% Cd alloys are examined. Diffusion in the nanometer regime and the states of defects are found to be important contributing factors to determine the shape memory effect, the variable martensitic transformations and the rubber like behavior, which are discussed in details.

Download Full-text

Effect of cobalt doping on thermoelastic martensitic transformations and physical properties of magnetic shape memory alloys Ni50 − x Co x Mn29Ga21

Physics of the Solid State ◽

10.1134/s1063783413120305 ◽

2013 ◽

Vol 55 (12) ◽

pp. 2413-2421 ◽

Cited By ~ 5

Author(s):

V. G. Pushin ◽

N. I. Kourov ◽

A. V. Korolev ◽

V. V. Marchenkov ◽

E. B. Marchenkova ◽

...

Keyword(s):

Shape Memory Alloys ◽

Physical Properties ◽

Shape Memory ◽

Martensitic Transformations ◽

Cobalt Doping ◽

Magnetic Shape Memory ◽

Magnetic Shape Memory Alloys ◽

Thermoelastic Martensitic Transformations

Download Full-text

Distinctive Features of the Phase Composition of Porous TiNi-based Alloys Obtained by Reaction and Diffusion Sintering

KnE Materials Science ◽

10.18502/kms.v2i1.780 ◽

2017 ◽

Vol 2 (1) ◽

pp. 52

Author(s):

N.V. Artyukhova ◽

Yu.F. Yasenchuk ◽

K.V. Almaeva ◽

A.S. Garin ◽

V.A. Novikov ◽

...

Keyword(s):

Phase Composition ◽

Solid Phase ◽

Structural Features ◽

Liquid Phase Sintering ◽

Reaction Sintering ◽

Ti2ni Phase ◽

Tini Phase ◽

And Diffusion ◽

Diffusion Sintering ◽

Reaction And Diffusion

The present article is concerned with questions of reaction and diffusion sintering of porous shape-memory TiNi-based alloys. The comparative analysis of structural features of the porous alloys obtained by diffusion sintering of TiNi powder and reaction sintering of Ti and Ni powders was conducted. It is observed that the main feature of structure of the porous alloys is related to fraction of the TiNi phase which occupies about 90 vol.% at diffusion sintering, and 20÷50 % of the total volume of multiphase alloy for reaction sintering. The mechanisms of the structure formation on the solid phase and liquid phase sintering stages of these methods were considered. The role of Ti2Ni phase during sintering was disclosed. The Ti2Ni phase not only provides the necessary quality of sintering, activates recrystallization processes for diffusion sintering, modifies the phase composition of the sintered specimen for reaction sintering, but also participates in the formation of the TiNi phase, increasing its fraction.

Download Full-text