scholarly journals Мартенситные превращения и эффект памяти формы биосовместимых сплавов TiNiMoAl

2021 ◽  
Vol 47 (6) ◽  
pp. 36
Author(s):  
А.Н. Моногенов ◽  
В.Э. Гюнтер ◽  
Е.С. Марченко ◽  
С.Г. Аникеев ◽  
В.Н. Ходоренко ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Change ◽  
Martensitic Transformations ◽  
Reverse Martensitic Transformation ◽  
Temperature Range

A study of martensitic transformations and characteristics of the shape memory effect of medical alloys (TH-10) alloyed with aluminum up to 4 at.% Al long the TiNiMo-TiMeMo section was carried out. Aluminum has a fairly smooth effect on the temperatures of the beginning and end of the direct and reverse martensitic transformation, as well as similar characteristics under load, which makes it possible to use alloying with aluminum as a method for controlling the temperature range of shape change with the shape memory effect.

Martensitic Transformation and Microstructural Characteristics in Copper Based Shape Memory Alloys

2012 ◽  
Vol 510-511 ◽  
pp. 105-110 ◽  
Author(s):  
Osman Adiguzel
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Martensitic Transformations ◽  
Microstructural Characteristics ◽  
Shape Memory Property ◽  
Martensite Variant ◽  
Cooperative Movement ◽  
Β Phase

Martensitic transformations are first order solid state phase transitions and occur in the materials on cooling from high temperature. Shape memory effect is an unusual property exhibited by certain alloy systems, and based on martensitic transformation. The shape memory property is characterized by the recoverability of previously defined shape or dimension when they are subjected to variation of temperature. The shape memory effect is facilitated by martensitic transformation, and shape memory properties are intimately related to the microstructures of the materials. Martensitic transformations occur as martensite variant with the cooperative movement of atoms on {110}β - type plane of austenite matrix. Martensitic transformations have diffusionless character, and the atomic movement is confined to interatomic lengths in the materials. The basic factors which govern the martensitic transformation are Bain distortion and homogeneous shears. Copper based alloys exhibit this property in metastable β-phase field.

Unexpected Constrained Twin Hierarchy in Equiatomic Ru-Based High Temperature Shape Memory Alloy Martensite

2013 ◽  
Vol 738-739 ◽  
pp. 195-199 ◽  
Author(s):  
Philippe Vermaut ◽  
Anna Manzoni ◽  
Anne Denquin ◽  
Frédéric Prima ◽  
Richard Portier
Keyword(s):  
High Temperature ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Martensitic Transformations ◽  
Single Transition

Among the different systems for high temperature shape memory alloys (SMA’s), equiatomic RuNb and RuTa alloys demonstrate both shape memory effect (SME) and MT temperatures above 800°C. Equiatomic compounds undergo two successive martensitic transformations, β (B2) → β’ (tetragonal) → β’’ (monoclinic), whereas out of stoechiometry alloys exhibit a single transition from cubic to tetragonal. In the case of two successive martensitic transformations, we expect to have a finer microstructure of the second martensite because it is supposed to develop inside the smallest twin elements of the former one. In equiatomic Ru-based alloys, if the first martensitic transformation is “normal”, the second one gives different unexpected microstructures with, for instance, twins with a thickness which is larger than the smallest spacing between twin variants of the first martensite. In fact, the reason for this unexpected hierarchy of the twins size is that the second martensitic transformation takes place in special conditions: geometrically, elastically and crystallographically constrained.

Martensitic transformation, ductility, and shape-memory effect of polycrystalline Ni56Mn25 –xFexGa19alloys

2005 ◽  
Vol 96 (8) ◽  
pp. 843-846 ◽  
Author(s):  
Yunqing Ma ◽  
Lihong Xu ◽  
Yan Li ◽  
Chengbao Jiang ◽  
Huibin Xu ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect

scholarly journals Fabrication and Shape Memory Characteristics of Highly Porous Ti-Nb-Mo Biomaterials

2017 ◽  
Vol 62 (2) ◽  
pp. 1367-1370 ◽  
Author(s):  
Y.-W. Kim ◽  
T.W. Mukarati
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Differential Scanning Calorimetric ◽  
Porous Scaffolds ◽  
High Porosity ◽  
Porous Ti ◽  
Human Body Temperature ◽  
Rapidly Solidified

AbstractNon-toxic Ti-Nb-Mo scaffolds were fabricated by sintering rapidly solidified alloy fibers for biomedical applications. Microstructure and martensitic transformation behaviors of the porous scaffolds were investigated by means of differential scanning calorimetric and X-ray diffraction. Theα″–βtransformation occurs in the as-solidified fiber and the sintered scaffolds. According to the compressive test of the sintered scaffolds with 75% porosity, they exhibit good superelasticity and strain recovery ascribed to the stress-induced martensitic transformation and the shape memory effect. Because of the high porosity of the scaffolds, an elastic modulus of 1.4 GPa, which matches well with that of cancellous bone, could be obtained. The austenite transformation finishing temperature of 77Ti-18Nb-5Mo alloy scaffolds is 5.1°C which is well below the human body temperature, and then all mechanical properties and shape memory effect of the porous 77Ti-18Nb-5Mo scaffolds are applicable for bon replacement implants.

Martensitic transformations γ-ɛ (α) and the shape-memory effect in aging high-strength manganese austenitic steels

2008 ◽  
Vol 106 (6) ◽  
pp. 630-640 ◽  
Author(s):  
V. V. Sagaradze ◽  
V. I. Voronin ◽  
Yu. I. Filippov ◽  
V. A. Kazantsev ◽  
M. L. Mukhin ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
High Strength ◽  
Martensitic Transformations ◽  
Austenitic Steels

scholarly journals Effect of Thermomechanical Cycling on Martensitic Transformation and Shape Memory Effect in 304 Austenitic Steel

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 901
Author(s):  
Jie Chen ◽  
Yonghao Zhang ◽  
Jiqiang Ge ◽  
Huabei Peng ◽  
Shuke Huang ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory ◽  
Austenitic Steel ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Annealing Temperature ◽  
Cycle Number ◽  
Thermomechanical Cycling ◽  
Ε Martensite ◽  
Optimum Annealing Temperature

To improve the shape memory effect (SME) of 304 austenitic steel effectively and efficiently, thermomechanical cycling, comprising deformation at room temperature and annealing, was applied. The influences of cycle number and annealing temperature on the SME and microstructures in 304 austenitic steel were investigated by light microscope (LM), X-ray diffraction (XRD), and transmission electron microscope (TEM). The shape recovery ratio was remarkably improved from 16% to 40% after two thermomechanical cycles. The optimum annealing temperature was 833 K in the process of thermomechanical cycling. The improved SME by thermomechanical cycling was mainly related to stress-induced ε martensite rather than stress-induced α’ martensite. The reason is that thermomechanical cycling can not only promote the occurrence of the stress-induced γ→ε martensitic transformation, but also suppress the subsequently stress-induced ε→α′ transformation.

scholarly journals The Effect of Subsequent Stress-Induced Martensite Aging on the Viscoelastic Properties of Aged NiTiHf Polycrystals

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1890
Author(s):  
Anton I. Tagiltsev ◽  
Elena Y. Panchenko ◽  
Ekaterina E. Timofeeva ◽  
Yuriy I. Chumlyakov ◽  
Ekaterina S. Marchenko ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Martensitic Transformation ◽  
Internal Friction ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Viscoelastic Properties ◽  
Oriented Growth ◽  
Compressive Stresses ◽  
Significant Change

This study investigated the effect of stress-induced martensite aging under tensile and compressive stresses on the functional and viscoelastic properties in Ni50.3Ti32.2Hf17.5 polycrystals containing dispersed H-phase particles up to 70 nm in size obtained by preliminary austenite aging at 873 K for 3 h. It was found that stress-induced martensite aging at 428 K for 12 h results in the appearance of a two-way shape memory effect of −0.5% in compression and +1.8% in tension. Moreover, a significant change in viscoelastic properties can be observed: an increase in internal friction (by 25%) and a change in elastic modulus in tensile samples. The increase in internal friction during martensitic transformation after stress-induced martensite aging is associated with the oriented growth of thermal-induced martensite. After stress-induced martensite aging, the elastic modulus of martensite (EM) increased by 8 GPa, and the elastic modulus of austenite (EA) decreased by 8 GPa. It was shown that stress-induced martensite aging strongly affects the functional and viscoelastic properties of material and can be used to control them.

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.

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