scholarly journals A strategy of designing high-entropy alloys with high-temperature shape memory effect

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Je In Lee ◽  
Koichi Tsuchiya ◽  
Wataru Tasaki ◽  
Hyun Seok Oh ◽  
Takahiro Sawaguchi ◽  
...  
Keyword(s):  
High Temperature ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Noble Metals ◽  
Alloy System ◽  
Equilibrium Temperature ◽  
High Entropy Alloys ◽  
Face Centered Cubic ◽  
High Entropy

Abstract Shape memory effect, the ability to recover a pre-deformed shape on heating, results from a reversible martensitic transformation between austenite and martensite phases. Here, we demonstrate a strategy of designing high-entropy alloys (HEAs) with high-temperature shape memory effect in the CrMnFeCoNi alloy system. First, we calculate the difference in Gibbs free energy between face-centered-cubic (FCC) and hexagonal-close-packed (HCP) phases, and find a substantial increase in thermodynamic equilibrium temperature between the FCC and HCP phases through composition tuning, leading to thermally- and stress-induced martensitic transformations. As a consequence, the shape recovery temperature in non-equiatomic CrMnFeCoNi alloys can be increased to 698 K, which is much higher than that of conventional shape memory alloys (SMAs) and comparable to that of B2-based multi-component SMAs containing noble metals (Pd, Pt, etc.) or refractory metals (Zr, Hf, etc.). This result opens a vast field of applications of HEAs as a novel class of cost-effective high-temperature SMAs.

scholarly journals Effect of Sm Doping on the Microstructure, Mechanical Properties and Shape Memory Effect of Cu-13.0Al-4.0Ni Alloy

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4007
Author(s):  
Qimeng Zhang ◽  
Bo Cui ◽  
Bin Sun ◽  
Xin Zhang ◽  
Zhizhong Dong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Strengthening Effect ◽  
Face Centered Cubic ◽  
Compressive Fracture ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Face Centered

The effects of rare earth element Sm on the microstructure, mechanical properties, and shape memory effect of the high temperature shape memory alloy, Cu-13.0Al-4.0Ni-xSm (x = 0, 0.2 and 0.5) (wt.%), are studied in this work. The results show that the Sm addition reduces the grain size of the Cu-13.0Al-4.0Ni alloy from millimeters to hundreds of microns. The microstructure of the Cu-13.0Al-4.0Ni-xSm alloys are composed of 18R and a face-centered cubic Sm-rich phase at room temperature. In addition, because the addition of the Sm element enhances the fine-grain strengthening effect, the mechanical properties and the shape memory effect of the Cu-13.0Al-4.0Ni alloy were greatly improved. When x = 0.5, the compressive fracture stress and the compressive fracture strain increased from 580 MPa, 10.5% to 1021 MPa, 14.8%, respectively. When the pre-strain is 10%, a reversible strain of 6.3% can be obtained for the Cu-13.0Al-4.0Ni-0.2Sm alloy.

Effect of aging on transformation behavior and shape memory effect of a CuAlNb high temperature shape memory alloy

2006 ◽  
Vol 41 (18) ◽  
pp. 6165-6167 ◽  
Author(s):  
Z. Y. Gao ◽  
Y. Wu ◽  
Y. X. Tong ◽  
W. Cai ◽  
Y. F. Zheng ◽  
...  
Keyword(s):  
High Temperature ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Transformation Behavior

Two way shape memory effect in NiTiHf high temperature shape memory alloy tubes

2019 ◽  
Vol 163 ◽  
pp. 1-13 ◽  
Author(s):  
C. Hayrettin ◽  
O. Karakoc ◽  
I. Karaman ◽  
J.H. Mabe ◽  
R. Santamarta ◽  
...  
Keyword(s):  
High Temperature ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect

scholarly journals Giant two-way shape memory effect in high-temperature Ni–Mn–Ga single crystal

2010 ◽  
Vol 10 ◽  
pp. 94-98 ◽  
Author(s):  
V.A. Chernenko ◽  
E. Villa ◽  
S. Besseghini ◽  
J.M. Barandiaran
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect

Relationship between Annealing and Shape Memory Effect of Shape Memory Polyurethane

2014 ◽  
Vol 936 ◽  
pp. 140-144 ◽  
Author(s):  
Jia Ying ◽  
Masaaki Nishikawa ◽  
Masaki Hojo
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Length Change ◽  
Recovery Ratio ◽  
High Entropy ◽  
Change Of State ◽  
Relationship Of ◽  
Shape Memory Polyurethane

The relationship of annealing and shape memory effect of uniaxially oriented shape memory polyurethane was studied; meanwhile a new method of adjusting shape recovery ratio by annealing was proposed for further consideration. Experiments were designed to compare the influence on length change from annealing and shape memory effect with shape memory polyurethane film at 65°C. We found that for shape memory polyurethane which had residual strain from material processing procedure, annealing and shape memory effect have the same effect on its length change if they are both carried out at the same temperature. It is because annealing and shape memory effect have the same mechanism, which is the change of state from low conformational entropy states to the recovery of a stable high entropy state in the polymer. Moreover, it is proved by experiment that shape recovery ratio of shape memory polyurethane can be adjusted by annealing.

Features of Crystallization of Rapidly Quenched Ni45Ti32Hf18Cu5 and Ni25Ti32Hf18Cu25 Alloys from Melt with High-Temperature Shape Memory Effect

2017 ◽  
Vol 62 (12) ◽  
pp. 1843-1847 ◽  
Author(s):  
A. V. Pushin ◽  
V. G. Pushin ◽  
T. E. Kuntsevich ◽  
N. N. Kuranova ◽  
V. V. Makarov ◽  
...  
Keyword(s):  
High Temperature ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect

scholarly journals Improvement of High-Temperature Shape-Memory Effect by Multi-Component Alloying for TiPd Alloys

2019 ◽  
Vol 60 (11) ◽  
pp. 2282-2291 ◽  
Author(s):  
Hiromichi Matsuda ◽  
Hirotaka Sato ◽  
Masayuki Shimojo ◽  
Yoko Yamabe-Mitarai
Keyword(s):  
High Temperature ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect

scholarly journals Microstructure Formation in Cast TiZrHfCoNiCu and CoNiCuAlGaIn High Entropy Shape Memory Alloys: A Comparison

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4227 ◽  
Author(s):  
Tetiana A. Kosorukova ◽  
Gregory Gerstein ◽  
Valerii V. Odnosum ◽  
Yuri N. Koval ◽  
Hans Jürgen Maier ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Microstructure Characterization ◽  
Microstructure Formation ◽  
High Entropy

The present study is dedicated to the microstructure characterization of the as-cast high entropy intermetallics that undergo a martensitic transformation, which is associated with the shape memory effect. It is shown that the TiZrHfCoNiCu system exhibits strong dendritic liquation, which leads to the formation of martensite crystals inside the dendrites. In contrast, in the CoNiCuAlGaIn system the dendritic liquation allows the martensite crystals to form only in interdendritic regions. This phenomenon together with the peculiarities of chemical inhomogeneities formed upon crystallization of this novel multicomponent shape memory alloys systems will be analyzed and discussed.

Hydrogen Enhances Shape Memory Effect of a Ferrous Face-Centered Cubic Alloy

2020 ◽  
Vol 51 (9) ◽  
pp. 4439-4441
Author(s):  
Motomichi Koyama ◽  
Chunxi Hao ◽  
Eiji Akiyama ◽  
Kaneaki Tsuzaki
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Face Centered Cubic ◽  
Face Centered
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