scholarly journals Structural phase transformations and shape memory effect in ZrCu along with Ni and Hf additions

2015 ◽  
Vol 33 ◽  
pp. 06005 ◽  
Author(s):  
Tetiana Kosorukova ◽  
Georgiy Firstov ◽  
Yuri Koval ◽  
Pavlo Verhovlyuk ◽  
Jan Van Humbeeck ◽  
...  
Keyword(s):  
Shape Memory ◽  
Phase Transformations ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Structural Phase ◽  
Structural Phase Transformations

The Concept of Physical Metric in the Thermomechanical Modeling of Phase Transformations With Emphasis on Shape Memory Alloy Materials

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Vassilis P. Panoskaltsis ◽  
Lazaros C. Polymenakos ◽  
Dimitris Soldatos
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Phase Transformations ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Material Model ◽  
Internal Variable ◽  
Theoretical Interest ◽  
Numerical Examples ◽  
Thermomechanical Modeling

In this work we derive a new version of generalized plasticity, suitable to describe phase transformations. In particular, we present a general multi surface formulation of the theory which is capable of describing the multiple and interacting loading mechanisms, which occur during phase transformations. The formulation relies crucially on the consideration of the intrinsic material (“physical”) metric as a primary internal variable and does not invoke any decomposition of the kinematical quantities into elastic and inelastic (transformation induced) parts. The new theory, besides its theoretical interest, is also important for application purposes such as the description and the prediction of the response of shape memory alloy materials. This is shown in the simplest possible setting by the introduction of a material model. The ability of the model in simulating several patterns of the experimentally observed behavior of these materials such as the pseudoelastic phenomenon and the shape memory effect is assessed by representative numerical examples.

Solid State Transformations and Equilibrium Crystal Structures of an Au-Cu Alloy with Shape Memory Effect

2012 ◽  
Vol 730-732 ◽  
pp. 859-864 ◽  
Author(s):  
Georgina Miranda ◽  
F.S. Silva ◽  
Delfim Soares
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Shape Memory ◽  
Phase Transformations ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Equilibrium Phase ◽  
Lattice Parameters ◽  
Solid State Transformation ◽  
Heating And Cooling

Au-50%Cu (at. %) alloy presents the shape memory effect (SME), which is dependent of the solid state transformation that happens during heating, after the introduction of an internal stress in the quenched state. The solid state phase transformation temperatures were determined by means of Differential Thermal Analysis (DTA), both in heating and cooling cycles. With the obtained DTA results, a sequence of high temperature X-ray diffraction (XRD) experiments were made, in order to confirm the presence of the solid state phase transformations and to determine their stable crystal structure and lattice parameters. These XRD results were compared with those obtained from the literature. The displacements of the lattice parameters were determined, for each equilibrium phase, for measurements at room temperature and at high temperature. The characteristics of the quenched samples were also studied in order to determine the phase transformations that are responsible for the shape memory effect in this alloy.

scholarly journals Phase Transformations, Microstructure and Shape Memory Effect of NiTiAg Alloy with Different Atomic Percentages (at. % Ag) Manufactured by Casting Method

2021 ◽  
Vol 39 (4A) ◽  
pp. 543-551
Author(s):  
Saja M. Hussein ◽  
Khansaa D. Salman ◽  
Ahmed A. Hussein
Keyword(s):  
Shape Memory ◽  
Phase Transformations ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Martensite Phase ◽  
Austenite Phase ◽  
Vacuum Arc ◽  
Casting Method ◽  
Vacuum Arc Remelting ◽  
Niti Matrix

In this paper, shape memory alloys (SMAs) (NiTi-based) have been manufactured by casting with a different atomic percentage of a silver element (0, 1, 2 and 3 at. % Ag) using a Vacuum Arc Remelting (VAR) furnace. The silver element is added to the binary alloys due to its excellent properties such as (anti-corrosion, anti-bacterial and high electrical conductivity), which make these alloys using in wider applications. These alloys with different atomic percentages (Ni55Ti45Ag0, Ni55Ti44Ag1, Ni55Ti43Ag2 and Ni55Ti42Ag3) have been manufactured. The successful manufacturing process has been achieved and proved via examinations and tests. The FESEM microscopic examinations show that the silver element has been distributed uniformly and homogeneously in the NiTi matrix. Moreover, the emergence of austenite phase, martensite phase and little amount impurities. Regarding the XRD examination, showed that there is an increase in the number of peaks of Ag phase with an increase in the atomic percentage of the silver element, as well to emergence of phase (Ti2Ni) upon heating, phase (Ti 002) upon cooling, and phase (Ni4Ti3) is not desired. The starting and finishing of the phase transformations have been determined for all samples by the DSC test. The Shape Memory Effect (SME) for the alloy (Ni50Ti42Ag3) is measured to be about 89.99%.

Surface Effects on Structural Phase Transformations in Nanosized Shape Memory Alloys

2013 ◽  
Vol 117 (15) ◽  
pp. 7895-7901 ◽  
Author(s):  
Zhen Zhang ◽  
Xiangdong Ding ◽  
Junkai Deng ◽  
Jian Cui ◽  
Jun Sun ◽  
...  
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Phase Transformations ◽  
Structural Phase ◽  
Surface Effects ◽  
Structural Phase Transformations

Intellectualization of Surface Layers, Working under Cyclic Loading and Reversing Friction

2015 ◽  
Vol 798 ◽  
pp. 440-446 ◽  
Author(s):  
Zhesfina Michailovna Blednova ◽  
Peter Olegovich Rusinov
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Structural Phase ◽  
Operating Conditions ◽  
Damping Capacity ◽  
Processing Modes ◽  
Martensitic State ◽  
Object Of Study ◽  
Resistant Layer

The object of study is a multi-layer composition «steel – a material with shape memory effect (SME) – wear-resistant layer» (TiNiHf - WC-Mo-Co). Ni was deposited as an adhesion layer. The sequence of functional layers deposition, their composition, thickness, structural-phase state and dispersion are determined by the operating conditions and operated by processing modes. To enhance durability and longevity it is recommended to form a layer with shape memory effect in a way that its temperature, given the increase in friction, corresponded to martensitic state and had an increased relaxation and damping capacity to inhibit cracking.

The structure–phase transformations and mechanical properties of the shape memory effect alloys based on the system Cu–Al–Ni

2017 ◽  
Vol 4 (3) ◽  
pp. 4758-4762 ◽  
Author(s):  
Alexey E. Svirid ◽  
Vladimir G. Pushin ◽  
Natalia N. Kuranova ◽  
Alexandr V. Luk'yanov ◽  
ArtemV. Pushin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Phase Transformations ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Structure Phase

Phase transformations and shape memory effect in copper-aluminium-manganese alloys

1988 ◽  
Vol 22 (6) ◽  
pp. 821-825 ◽  
Author(s):  
J.J. Counioux ◽  
J.L. Macqueron ◽  
M. Robin ◽  
J.M. Scarabello
Keyword(s):  
Shape Memory ◽  
Phase Transformations ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Manganese Alloys
Sign in / Sign up

Export Citation Format

Share Document