Pseudoelasticity of shape-memory titanium–nickel films subjected to dynamic nanoindentation

2004 ◽  
Vol 84 (21) ◽  
pp. 4274-4276 ◽  
Author(s):  
X.-G. Ma ◽  
K. Komvopoulos
Keyword(s):  
Shape Memory ◽  
Nickel Films ◽  
Titanium Nickel ◽  
Dynamic Nanoindentation

A Shape-Corrective Shunt-Passer using a Titanium-Nickel Alloy

Neurosurgery ◽  
1991 ◽  
Vol 28 (5) ◽  
pp. 725-726 ◽  
Author(s):  
Shizuo Oi ◽  
Satoshi Matsumoto
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Nickel Alloy ◽  
Titanium Nickel

Abstract The authors describe a new shunt-passer using a shape memory alloy that is malleable enough to be molded into any contour and is straightened automatically during autoclave sterilization.

In situ Transmission Electron Microscopy and Nanoindentation Studies of Phase Transformation and Pseudoelasticity of Shape-memory Titanium-nickel Films

2005 ◽  
Vol 20 (7) ◽  
pp. 1808-1813 ◽  
Author(s):  
X.-G. Ma ◽  
K. Komvopoulos
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Transformation ◽  
Shape Memory ◽  
Heating And Cooling ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Titanium Nickel ◽  
In Situ Heating

Transmission electron microscopy (TEM) and nanoindentation, both with in situ heating capability, and electrical resistivity measurements were used to investigate phase transformation phenomena and thermomechanical behavior of shape-memory titanium-nickel (TiNi) films. The mechanisms responsible for phase transformation in the nearly equiatomic TiNi films were revealed by heating and cooling the samples inside the TEM vacuum chamber. Insight into the deformation behavior of the TiNi films was obtained from the nanoindentation response at different temperatures. A transition from elastic-plastic to pseudoelastic deformation of the martensitic TiNi films was encountered during indentation and heating. In contrast to the traditional belief, the martensitic TiNi films exhibited a pseudoelastic behavior during nanoindentation within a specific temperature range. This unexpected behavior is interpreted in terms of the evolution of martensitic variants and changes in the mobility of the twinned structures in the martensitic TiNi films, observed with the TEM during in situ heating.

Planar Extrinsic Biasing Of Thin Film Shape-Memory MEMS Actuators.

2002 ◽  
Vol 750 ◽  
Author(s):  
D. S. Grummon ◽  
R. Gotthardt ◽  
T. LaGrange
Keyword(s):  
Thin Film ◽  
Shape Memory ◽  
Active Element ◽  
High Surface ◽  
Volume Ratio ◽  
Martensite Phase ◽  
Mems Actuators ◽  
Titanium Nickel ◽  
Mechanical Elements ◽  
Force Displacement

ABSTRACTAlthough slow and dissipative, sputtered thin-film shape-memory alloys like equiatomic titanium-nickel can exert a large ohmically-excited force displacement product when deployed in photolithographically micromachined actuators. They give energy densities far exceeding those typically produced by competing microactuator materials [1], and their size can probably be scaled down to the nanometer range (where the benefits of high surface to volume ratio are best exploited for speed and efficiency). But a large, energetic, and resettable actuation stroke is possible only if some agency has imparted a non-trivial initial plastic strain, of between one and five percent, to the martensite phase. Is not always obvious how this strain is to be achieved when discrete mechanical manipulation of the active element is difficult. Furthermore, for cyclic actuation, a resetting-force that periodically re-deforms the martensite during the cooling interval must arise naturally from mechanical elements in the design. Here, several methods responding these requirements are discussed in relation to various kinematic themes.

Dependence of shape memory effect and superelasticity on the number of variants of dispersed particles in titanium-nickel single crystals

2002 ◽  
Vol 47 (7) ◽  
pp. 510-514 ◽  
Author(s):  
Yu. I. Chumlyakov ◽  
E. Yu. Panchenko ◽  
I. V. Kireeva ◽  
S. P. Efimenko ◽  
V. B. Aksenov ◽  
...  
Keyword(s):  
Shape Memory ◽  
Single Crystals ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Dispersed Particles ◽  
Titanium Nickel

scholarly journals Влияние поверхностного слоя на комплекс свойств тонкой проволоки из сплава на основе TiNi

2018 ◽  
Vol 44 (18) ◽  
pp. 10
Author(s):  
В.Э. Гюнтер ◽  
Е.С. Марченко ◽  
С.В. Гюнтер ◽  
Г.А. Байгонакова
Keyword(s):  
Surface Layer ◽  
Shape Memory ◽  
Layer Structure ◽  
Martensitic Transformations ◽  
Alloy Wire ◽  
Characteristic Temperatures ◽  
Titanium Nickel ◽  
Strength And Plasticity ◽  
Strength And Plasticity Characteristics ◽  
Accumulated Deformation

AbstractWe have studied the influence of the surface layer on the parameters of the multiply repeated shape memory effect, developing stresses, characteristic temperatures, and intervals of martensitic transformations in thin (1 mm diameter) wires made of TiNi-based alloys. Examination of the surface layer structure showed that, in 1-mm-diameter TN-1V grade alloy wire, the oxide layer is about 15 μm thick and consists mostly of titanium, nickel, oxygen, and carbon. Removal of this surface layer leads to an increase in the maximum accumulated deformation, shift of the temperature interval of formation toward higher temperatures, and increase in the strength and plasticity characteristics.

Sign in / Sign up

Export Citation Format

Share Document