Fracture modes during severe plastic deformation of NiTi shape memory alloys

2015 ◽  
Vol 116 (7) ◽  
pp. 737-744
Author(s):  
Corneliu M. Craciunescu ◽  
Rui J. C. Silva ◽  
Francisco M. Braz Fernandes
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Fracture Modes ◽  
Niti Shape Memory Alloys

GRADED TRANSITIONS IN Ni-Ti SHAPE MEMORY ALLOYS PROCESSED BY SEVERE PLASTIC DEFORMATION

2012 ◽  
Vol 05 (04) ◽  
pp. 1250049 ◽  
Author(s):  
CORNELIU M. CRACIUNESCU ◽  
FRANCISCO M. BRAZ FERNANDES
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Deformation Gradient ◽  
Front Surface ◽  
Single Step ◽  
Angular Pressing ◽  
State Of Stress ◽  
Niti Shape Memory Alloys

NiTi shape memory alloys were subjected to a single step severe plastic deformation via the equal channel angular pressing (ECAP). The properties were analyzed by comparing the transformation characteristics for sections across the thickness of the deformed sample, with focus on the deformation gradient in the outer layers of the materials and the front surface that gradually engages in the deformation. A gradient related to the crystallinity and the state of stress was observed across the thickness of the deformed sample.

Plastic deformation of NiTi shape memory alloys

2013 ◽  
Vol 61 (1) ◽  
pp. 67-78 ◽  
Author(s):  
Tawhid Ezaz ◽  
J. Wang ◽  
Huseyin Sehitoglu ◽  
H.J. Maier
Keyword(s):  
Plastic Deformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Niti Shape Memory Alloys

Nanostructured TiNi-based shape memory alloys processed by severe plastic deformation

2005 ◽  
Vol 410-411 ◽  
pp. 386-389 ◽  
Author(s):  
V.G. Pushin ◽  
V.V. Stolyarov ◽  
R.Z. Valiev ◽  
T.C. Lowe ◽  
Y.T. Zhu
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Shape Memory Alloys ◽  
Shape Memory

Martensitic Transformation and Mechanical Behavior of TiNi Shape Memory Alloys after Severe Plastic Deformation

2006 ◽  
Vol 503-504 ◽  
pp. 419-424
Author(s):  
Koichi Tsuchiya ◽  
M. Inuzuka ◽  
Akihide Hosokawa ◽  
Dacian Tomus ◽  
Hiroyuki Nakayama ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Martensitic Transformation ◽  
Severe Plastic Deformation ◽  
Cold Rolling ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Limited Extent ◽  
Dsc Analysis ◽  
Stress Plateau ◽  
Nanocrystalline And Amorphous

Thermal- and stress-induced martensitic transformation was investigated on TiNi shape memory alloys subjected to severe plastic deformation (SPD) by cold rolling. TEM observation revelaed the sample is a mixture of nanocrystalline and amorphous after 40% cold rolling. DSC analysis suggested that the martensitic transformation was suppressed when the thickness reduction was over 25% reduction. Aging at lower temperatures (573 ~ 673 K, 3.6 ks) restores the phase transformations, but to a limited extent. The stress-strain curves of nanocrystalline/amorphous TiNi are characterized by absence of stress-plateau and small hysteresis.

scholarly journals Structural Change in Ni-Fe-Ga Magnetic Shape Memory Alloys after Severe Plastic Deformation

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1939 ◽  
Author(s):  
Gheorghe Gurau ◽  
Carmela Gurau ◽  
Felicia Tolea ◽  
Vedamanickam Sampath
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
High Speed ◽  
High Pressure Torsion ◽  
Magnetic Shape Memory ◽  
Two Phase ◽  
Ultrafine Grained

Severe plastic deformation (SPD) is widely considered to be the most efficient process in obtaining ultrafine-grained bulk materials. The aim of this study is to examine the effects of the SPD process on Ni-Fe-Ga ferromagnetic shape memory alloys (FSMA). High-speed high-pressure torsion (HSHPT) was applied in the as-cast state. The exerted key parameters of deformation are described. Microstructural changes, including morphology that were the result of processing, were investigated by optical and scanning electron microscopy. Energy-dispersive X-ray spectroscopy was used to study the two-phase microstructure of the alloys. The influence of deformation on microstructural features, such as martensitic plates, intragranular γ phase precipitates, and grain boundaries’ dependence of the extent of deformation is disclosed by transmission electron microscopy. Moreover, the work brings to light the influence of deformation on the characteristics of martensitic transformation (MT). Vickers hardness measurements were carried out on disks obtained by SPD so as to correlate the hardness with the microstructure. The method represents a feasible alternative to obtain ultrafine-grained bulk Ni-Fe-Ga alloys.

Thermomechanical Treatment of Ti-Ni-Based Shape Memory Alloys Using Severe Plastic Deformation

2003 ◽  
Vol 426-432 ◽  
pp. 2765-2770 ◽  
Author(s):  
I. Khmelevskaya ◽  
I.B. Trubitsyna ◽  
Sergey Prokoshkin ◽  
Sergey V. Dobatkin ◽  
E.V. Tatyanin ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Thermomechanical Treatment

scholarly journals Severe Plastic Deformation on Powder Metallurgy Cu–Al–Ni Shape Memory Alloys

2015 ◽  
Vol 2 ◽  
pp. S747-S750 ◽  
Author(s):  
G.A. López ◽  
I. López-Ferreño ◽  
A.R. Kilmametov ◽  
T. Breczewski ◽  
B.B. Straumal ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Powder Metallurgy ◽  
Severe Plastic Deformation ◽  
Shape Memory Alloys ◽  
Shape Memory

Amorphization and crystallization characteristics of TiNi shape memory alloys by severe plastic deformation

2009 ◽  
Vol 3 (3) ◽  
pp. 325-328
Author(s):  
Jun-tao Li ◽  
Wei-dong Miao ◽  
Yu-ling Hu ◽  
Yan-jun Zheng ◽  
Li-shan Cui
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Shape Memory Alloys ◽  
Shape Memory
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