Influence of chemical composition and pre-heating temperature on the structure and martensitic transformation in porous TiNi-based shape memory alloys, produced by self-propagating high-temperature synthesis

2013 ◽  
Vol 32 ◽  
pp. 81-89 ◽  
Author(s):  
N. Resnina ◽  
S. Belayev ◽  
A. Voronkov
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Heating Temperature ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

Martensitic Transformation of High-Entropy and Medium-Entropy Shape Memory Alloys

2021 ◽  
Vol 1016 ◽  
pp. 1802-1810
Author(s):  
Hiromichi Matsuda ◽  
Masayuki Shimojo ◽  
Hideyuki Murakami ◽  
Yoko Yamabe-Mitarai
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Transformation Temperature ◽  
Solid Solution Hardening ◽  
Solution Hardening ◽  
High Entropy ◽  
The One

As new generation of high-temperature shape memory alloys, high-entropy alloys (HEAs) have been attracted for strong solid-solution hardened alloys due to their severe lattice distortion and sluggish diffusion. TiPd is the one potential high-temperature shape memory alloys because of its high martensitic transformation temperature above 500 °C. As constituent elements, Zr expected solid-solution hardening, Pt expected increase of transformation temperature, Au expected keeping transformation temperature, and Co expected not to form harmful phase. By changing the alloy composition slightly, two HEAs and two medium entropy alloys (MEAs) were prepared. Only two MEAs, Ti45Zr5Pd25Pt20Au5, and Ti45Zr5Pd25Pt20Co5 had the martensitic transformation. The perfect recovery was obtained in Ti45Zr5Pd25Pt20Co5 during the repeated thermal cyclic test, training, under 200 MPa. On the other hand, the small irrecoverable strain was remained in Ti45Zr5Pd25Pt20Au5 during the training under 150 MPa because of the small solid-solution hardening effect. It indicates that Ti45Zr5Pd25Pt20Co5 is the one possible HT-SMA working between 342 and 450 °C.

Temperature Dependence and Martensitic Transformation of Ti50Pt50 Shape Memory Alloys

2014 ◽  
Vol 1019 ◽  
pp. 379-384
Author(s):  
M.P. Mashamaite ◽  
Hasani Rich Chauke ◽  
Rosinah Mahlangu ◽  
P.E. Ngoepe
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Temperature Dependence ◽  
Effect Of Temperature ◽  
Displacive Transformation ◽  
B2 Phase ◽  
Recent Experimental Work

Shape memory alloys (SMAs) are a fascinating group of metals that have two remarkable properties, the shape memory effect and superelasticity. The TiPt structure with the B2 phase has been reported to undergo a reversible displacive transformation to B19 martensite at about 1200K. However, this system could serve in principle as the basis of high-temperature shape memory alloys. Molecular dynamics study of martensitic transformation in platinum titanium alloys was performed to investigate the effect of temperature dependence on B2 and B19 structures at 50 at.%Pt. The NPT ensemble was used to determine the properties of these systems and we found good comparisons with recent experimental work. The temperature dependence of TiPt shows potential martensitic change when B19 is heated to extreme high temperatures of 273K up to 1573K.

Evolutions of Microstructure and Phase Transformation in Cu-Al-Fe-Nb/Ta High-Temperature Shape Memory Alloys

2015 ◽  
Vol 833 ◽  
pp. 67-70
Author(s):  
Shui Yuan Yang ◽  
Cui Ping Wang ◽  
Yu Su ◽  
Xing Jun Liu
Keyword(s):  
Phase Transformation ◽  
High Temperature ◽  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Transformation Behavior ◽  
Two Phase ◽  
Phase Transformation Behavior ◽  
Three Phase

The evolutions of microstructure and phase transformation behavior of Cu-Al-Fe-Nb/Ta high-temperature shape memory alloys under the quenched and aged states were investigated in this study, including Cu-10wt.% Al-6wt.% Fe, Cu-10wt.% Al-4wt.% Fe-2wt.% Nb and Cu-10wt.% Al-4wt.% Fe-2wt.% Ta three types alloys. The obtained results show that after quenching, Cu-10wt.% Al-6wt.% Fe alloy exhibits two-phase microstructure of β′1 martensite + Fe (Al,Cu) phase; Cu-10wt.% Al-4wt.% Fe-2wt.% Nb alloy also has two-phase microstructure of (β′1 + γ′1 martensites) + Nb (Fe,Al,Cu)2 phase; Cu-10wt.% Al-4wt.% Fe-2wt.% Ta alloy is consisted of three-phase of (β′1 + γ′1 martensites) + Fe (Al,Cu,Ta) + Ta2(Al,Cu,Fe)3 phases. However, α (Cu) phase precipitates after aging for three alloys; and Fe (Al,Cu,Nb) phase is also present in Cu-10wt.% Al-4wt.% Fe-2wt.% Nb alloy. All the studied alloys exhibit complicated martensitic transformation behaviors resulted from the existence of two types martensites (β′1 and γ′1).

Laser ignition in Self-propagating High temperature Synthesis of porous NiTinol Shape Memory Alloy

2017 ◽  
Vol 193 ◽  
pp. 54-57 ◽  
Author(s):  
C.A. Biffi ◽  
P. Bassani ◽  
Zahra Sajedi ◽  
P. Giuliani ◽  
A. Tuissi
Keyword(s):  
High Temperature ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Laser Ignition ◽  
Temperature Synthesis ◽  
High Temperature Synthesis
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