Application Temperature Range of Temperature Memory Effect in Deformed TiNi Alloys

2014 ◽  
Vol 787 ◽  
pp. 300-306
Author(s):  
Tian Wei Liu ◽  
Yan Jun Zheng ◽  
Li Shan Cui
Keyword(s):  
Memory Effect ◽  
Martensite Transformation ◽  
High Deformation ◽  
Temperature Range ◽  
Temperature Memory Effect ◽  
Cold Rolled ◽  
Reverse Martensite Transformation

The application temperature range of temperature memory effect (TME) in deformed TiNi alloys was studied in this paper. The TME could be used in a wider temperature range when the specimen cold-rolled in a high deformation. And, the “highest” application temperature of TME could increase with the deformation, and finally rise to 573K with deformed 30%. This temperature no longer changes in higher deformations, while the characteristic of TME still increase with the deformation below 573K. This is due to the dislocation texture and deform-induced martensite structures restrain the reverse martensite transformation. And the restraint disappears when specimens are annealed more than 573K.

Effect of Annealing Temperature on the Transformation Temperature and Texture of Ni47Ti44Nb9 Cold-Rolled Plate

2012 ◽  
Vol 557-559 ◽  
pp. 1281-1287 ◽  
Author(s):  
Zhao Wei Feng ◽  
Xu Jun Mi ◽  
Jiang Bo Wang ◽  
Zhi Shan Yuan ◽  
Jin Zhou
Keyword(s):  
Transformation Temperature ◽  
Martensite Transformation ◽  
Annealing Temperature ◽  
Rolled Plate ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Cold Rolled ◽  
Reverse Martensite Transformation ◽  
Rolled Plates

Transformation behaviors and texture of Ni47Ti44Nb9 cold-rolled plates were studied by differential scanning calorimetry and X-ray diffraction test. R phase transformation does not occur in Ni47Ti44Nb9cold-rolled plate annealed at 350°C-750°C followed by quenching into the water. Martensite transformation temperature first increases and then decreases with increment of annealing temperature, and the maximum achieves at 700°C. The heat of reverse martensite transformation increases, while hardness decreases as annealing temperature increases. The major texture of cold-rolled plate is {332} and spread from {332} to {110}. When the annealing temperature is above 600°C, the major textures are {332} and {111} recrystallization texture in secondary cold-rolled plate.

Rational direct synthesis of [Fe(Htrz)2(trz)](BF4) polymorphs: temperature and concentration effects.

2021 ◽  
Author(s):  
Marlene Palluel ◽  
Liza el Khoury ◽  
Nathalie Daro ◽  
Sonia Buffière ◽  
Michaël Josse ◽  
...  
Keyword(s):  
Memory Effect ◽  
Spin Crossover ◽  
Direct Synthesis ◽  
Large Temperature ◽  
Concentration Effects ◽  
Temperature Range ◽  
Temperature And Concentration Effects

The [Fe(Htrz)2trz](BF4) compound is probably the most studied in the spin crossover (SCO) community since it exhibits switching properties with a large temperature range of memory effect, just above room...

Texture and Ductility of Ni3Al Foils

2011 ◽  
Vol 306-307 ◽  
pp. 116-119
Author(s):  
Masahiko Demura ◽  
Ya Xu ◽  
Toshiyuki Hirano
Keyword(s):  
Grain Boundary ◽  
Grain Growth ◽  
Memory Effect ◽  
Texture Evolution ◽  
High Mobility ◽  
Two Stage ◽  
Texture Memory ◽  
Highly Effective ◽  
Cold Rolled

This article presents the texture evolution and the ductility improvement of the cold-rolled foils of boron-free Ni3Al during the recrystallization and the subsequent grain growth. The cold-rolled foils had sharp {110} textures. After the recrystallization at 873K/0.5h, the texture was disintegrated with several texture components. Interestingly, most of them had a single rotation relationship. i.e. 40˚ around <111>. With the progress of the grain growth, however, the texture returned to the sharp, cold-rolled textures. This two-stage texture evolution, called as “Texture memory effect”, was explained assuming a high mobility of the grain boundary with the 40˚<111> rotation relationship. The texture returning was highly effective to improve the ductility of the foils.

scholarly journals Межфазные напряжения и аномальный вид кривых псевдоупругой деформации в кристаллах сплава Ni-=SUB=-49-=/SUB=-Fe-=SUB=-18-=/SUB=-Ga-=SUB=-27-=/SUB=-Co-=SUB=-6-=/SUB=-, деформированных сжатием в направлении оси [011]-=SUB=-A-=/SUB=-

2019 ◽  
Vol 89 (6) ◽  
pp. 873
Author(s):  
Г.А. Малыгин ◽  
В.И. Николаев ◽  
В.М. Крымов ◽  
С.А. Пульнев ◽  
С.И. Степанов
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Elastic Moduli ◽  
Sharp Decrease ◽  
Transformation Kinetics ◽  
Sharp Drop ◽  
Interfacial Stresses ◽  
Temperature Range ◽  
Deformation Curves

AbstractWe have performed experimental and theoretical investigation of the anomalous form of the compression diagrams and shape memory restoration curves in Ni_49Fe_18Ga_27Co_6 alloy crystals deformed by uniaxial compression along the [011]_ A crystallographic direction ( A -austenite) in the temperature range of 200–350 K. It is found that in the investigated temperature range, all compression diagrams contain anomalous segments of smooth and sharp decrease in deforming stresses. It is shown that the segments of a smooth decrease in stress are associated with peculiarities in martensite reaction L1_2 → 14M, while segments of a sharp drop are due to instability of martensite reactions 14M → L1_0 and L1_2 → L1_0. A possible source of reaction instability is associated with interfacial stresses at the interfaces between the martensite and austenite phases (lamellas) due to different elastic moduli of contacting phases. The magnitude of these stresses is significant in the case of 14M → L1_0 and L1_2 → L1_0 transformations, which induces a sharp drop of the deforming stress, while the restoration of the shape memory effect is of a burst nature. It is established that the contribution of interfacial stresses to the free energy of martensite transformation is smaller than the dissipative (entropy) contribution to this energy; however, interfacial stresses higher than a certain threshold strongly affect transformation kinetics and, hence, determine the strongly anomalous shape of pseudoelastic deformation curves and burst restoration of the shape memory effect.

scholarly journals Anneal hardening effect in sintered copper alloys

2002 ◽  
Vol 34 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Svetlana Nestorovic ◽  
Boran Milicevic ◽  
Desimir Markovic
Keyword(s):  
Electrical Conductivity ◽  
Cold Rolling ◽  
Copper Alloys ◽  
Recrystallization Temperature ◽  
Temperature Range ◽  
Hardening Effect ◽  
Sintered Copper ◽  
Anneal Hardening ◽  
Cold Rolled

Samples of copper and copper alloys CuNi and CuNiAl were prepared by a powder metallurgical method and were then subjected to cold rolling with different degrees of deformation. Copper and copper alloys in the cold-rolled state were isochronally annealed up to the recrystallization temperature during which hardness and electrical conductivity were measured. This investigation shows that the anneal hardening effect occurs in a temperature range of 450 - 650 K, followed with an increase in hardness of alloys.

Effect of Cold Rolling on the Damping of As Cast Cu-Al-Mn Shape Memory Alloys

2008 ◽  
Vol 137 ◽  
pp. 155-162 ◽  
Author(s):  
Agnieszka Mielczarek ◽  
Yvonne Wöckel ◽  
Werner Riehemann
Keyword(s):  
Dislocation Density ◽  
Cold Rolling ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Cold Work ◽  
Amplitude Dependence ◽  
Aluminium Content ◽  
Aging Effects ◽  
High Deformation ◽  
Cold Rolled

The ductility of Cu – Al – Mn shape memory alloys at room temperature depends on the aluminium content. High aluminium contents make Cu – Al – Mn very brittle and unsuitable for plastic shaping. Two Cu – Al – Mn shape memory alloys were investigated. The ductile alloy CuAl7.8Mn9.5 (all contents in wt. %) could be easily cold rolled by 86 %. The alloy CuAl12Mn4.3 could be cold rolled by only 12 - 14 %. The amplitude dependence of damping of austenitic specimens increased with increasing degree of cold work, whereas the damping of martensiticaustenitic specimens decreased. These observations can be explained by the creation of stress induced martensite and therefore by new moveable interfaces like phase- and twin boundaries, which contribute to damping. Plastic deformation increases the dislocation density, too. Both the increase of dislocation density and the increase of martensite content can lead to a decrease of damping mainly for high deformation degrees. Same shape memory alloys have shown negligible hardness increase during cold rolling, too. This behaviour, untypical for metals, can be explained by the generation of new martensite and by the fact that the hardness of martensite is smaller than the hardness of austenite. Some aging effects of the specimen after cold rolling, which lead to decrease of damping, were detected. This can be explained by pinning of moveable interfaces by point defects and/or retransformation of martensite into austenite.

Study of Temperature Memory Effect During the Thermal Cycling in Hydraulic Systems

2015 ◽  
Vol 44 (4) ◽  
pp. 20140138 ◽  
Author(s):  
Gigi Vitel ◽  
Bogdan Pricop ◽  
Marius-Gabriel Suru ◽  
Nicoleta Monica Lohan ◽  
Leandru-Gheorghe Bujoreanu
Keyword(s):  
Thermal Cycling ◽  
Memory Effect ◽  
Hydraulic Systems ◽  
Temperature Memory Effect
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