Microstructure, thermomechanical and shape memory properties of two-phase Ni–Mn–Fe–Ga high-temperature shape memory alloys with B addition

2013 ◽  
Vol 37 ◽  
pp. 1-6 ◽  
Author(s):  
Shuiyuan Yang ◽  
Cuiping Wang ◽  
Zhan Shi ◽  
Xingjun Liu
2006 ◽  
Vol 2006 (0) ◽  
pp. 75-76
Author(s):  
Hideki HOSODA ◽  
Toshiyuki KAWAMURA ◽  
Tomonari INAMURA ◽  
Kenji WAKASHIMA ◽  
Shuichi MIYAZAKI

1994 ◽  
Vol 360 ◽  
Author(s):  
Jeno Beyer ◽  
Jan.H. Mulder

AbstractThe functional properties of Shape Memory Alloys (SMA's) are used succesfully at present in a variety of industrial and medical applications. The use of these materials in smart structures is now emerging in the field of aeronautic/space technology. Many applications require higher operating temperatures than available to date, or higher cooling rates and/or a higher number of cycles. For this purpose the properties and fabricability of commercial alloys as Ni-Ti-(X), Cu-Al-Ni or Cu-Zn-Al are being adjusted and improved. Other feasible alloys are being developed. The research and development is directed towards the control of the stress, strain, temperature and time dependence of shape memory properties for a stable in-service behaviour. In this paper the various approaches taken up in recent years by academic and industrial laboratories for developing high temperature SMA's are reviewed.


2015 ◽  
Vol 833 ◽  
pp. 67-70
Author(s):  
Shui Yuan Yang ◽  
Cui Ping Wang ◽  
Yu Su ◽  
Xing Jun Liu

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).


Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 798 ◽  
Author(s):  
Yuki Hattori ◽  
Takahiro Taguchi ◽  
Hee Kim ◽  
Shuichi Miyazaki

Ti–Ni–Pd shape memory alloys are promising candidates for high-temperature actuators operating at above 373 K. One of the key issues in developing high-temperature shape memory alloys is the degradation of shape memory properties and dimensional stabilities because plastic deformation becomes more pronounced at higher working temperature ranges. In this study, the effect of the Ti:(Ni + Pd) atomic ratio in TixNi70−xPd30 alloys with Ti content in the range from 49 at.% to 52 at.% on the martensitic transformation temperatures, microstructures and shape memory properties during thermal cycling under constant stresses were investigated. The martensitic transformation temperatures decreased with increasing or decreasing Ti content from the stoichiometric composition. In both Ti-rich and Ti-lean alloys, the transformation temperatures decreased during thermal cycling and the degree of decrease in the transformation temperatures became more pronounced as the composition of the alloy departed from the stoichiometric composition. Ti2Pd and P phases were formed during thermal cycling in Ti-rich and Ti-lean alloys, respectively. Both Ti-rich and Ti-lean alloys exhibited superior dimensional stabilities and excellent shape memory properties with higher recovery ratio and larger work output during thermal cycling under constant stresses when compared with the alloys with near-stoichiometric composition.


1991 ◽  
Vol 246 ◽  
Author(s):  
R. Kainuma ◽  
H. Nakano ◽  
K. Oikawa ◽  
K. Ishida ◽  
T. Nishizawa

AbstractAn attempt to develop a new type of high temperature shape memory alloys based on the Ni-Al system has been made through microstructural control. Addition of Fe or Mn to the binary Ni-Al alloy results in the formation of a ductile fcc phase in an extremely brittle P matrix phase, leading to an improvement in its ductility. These ductile alloys with β + γ two-phase structure in the Ni-Al-Fe, Ni-Al-Mn and Ni-Al-Mn-Fe systems exhibit a shape memory effect due to a thermoelastic martensitic transformation in the temperature range between -100°C and 700°C; besides, the transformation temperatures are easily controlled by annealing at an appropriate temperature. These alloys are expected to be a new group of shape memory alloys which operate at elevated temperatures.


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