Phase transformation and microstructure of quaternary TiNiHfCu high temperature shape memory alloys

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).

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Microstructure and Phase Transformation Behavior of Ni-Mn-Fe High-Temperature Shape Memory Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.833.63 ◽

2015 ◽

Vol 833 ◽

pp. 63-66

Author(s):

Cui Ping Wang ◽

Yu Ding Liu ◽

Shui Yuan Yang ◽

Xing Jun Liu

Keyword(s):

Phase Transformation ◽

High Temperature ◽

Shape Memory Alloys ◽

Shape Memory ◽

Transformation Behavior ◽

Phase Transformation Behavior ◽

Heating And Cooling ◽

High Transformation ◽

Irreversible Phase Transformation ◽

Very High

The microstructure and phase transformation behavior of Ni-Mn-Fe high-temperature shape memory alloys including Ni40+xFe10Mn50-x (x = 0, 10) were investigated. The results show that both two alloys exhibit single fcc γ phase annealed at 900°C for 1 day. When these quenched alloys are again annealed at 500°C for 20 days, they almost exhibit main tetragonal θ martensite. The microstructural evolutions are consistent with the results of phase transformation measurements. It is clearly found that there is an irreversible phase transformation around 480°C ~ 570°C, which is associated with the formation of tetragonal θ martensite from γ phase. Afterwards, the reversible martensitic transformation occurs during heating and cooling with very high transformation temperature.

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Effect of yttrium on martensite-austenite phase transformation temperatures and high temperature oxidation kinetics of Ti-Ni-Hf high-temperature shape memory alloys

Metals and Materials International ◽

10.1007/s12540-016-5130-x ◽

2016 ◽

Vol 22 (2) ◽

pp. 204-208 ◽

Cited By ~ 5

Author(s):

Jeoung Han Kim ◽

Kyong Min Kim ◽

Jong Taek Yeom ◽

Sung Young

Keyword(s):

Phase Transformation ◽

High Temperature ◽

Shape Memory Alloys ◽

Shape Memory ◽

Oxidation Kinetics ◽

High Temperature Oxidation ◽

Austenite Phase ◽

Temperature Oxidation ◽

Transformation Temperatures ◽

Kinetics Of

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High-Temperature Shape Memory Alloys Based on Ti-Platinum Group Metals Compounds

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.2541 ◽

2014 ◽

Vol 783-786 ◽

pp. 2541-2545 ◽

Cited By ~ 10

Author(s):

Yoko Yamabe-Mitarai ◽

Abdul Wadood ◽

Raju Arockiakumar ◽

Toru Hara ◽

Madoka Takahashi ◽

...

Keyword(s):

Phase Transformation ◽

High Temperature ◽

Phase Equilibria ◽

Shape Memory Alloys ◽

Shape Memory ◽

Transformation Temperature ◽

Shape Recovery ◽

Platinum Group Metals ◽

Phase Transformation Temperature ◽

Temperature Phase

The effect of alloying to TiPd and TiPt on phase transformation temperature, phase equilibria, and shape recovery were investigated for TiPt and TiPd base high-temperature shape memory alloys. Ru, Ir, Co and Zr were chosen for additional elements and Zr was found as the most effective element to improve shape recovery of TiPd and TiPt.

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Mechanical Properties of (Pt, Ir)Ti

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.1987 ◽

2005 ◽

Vol 475-479 ◽

pp. 1987-1990 ◽

Cited By ~ 3

Author(s):

Yoko Yamabe-Mitarai ◽

Toru Hara ◽

Seiji Miura ◽

Hideki Hosoda

Keyword(s):

Phase Transformation ◽

High Temperature ◽

Shape Memory Alloys ◽

Shape Memory ◽

High Strength ◽

Dislocation Motion ◽

Phase Transformation Temperature ◽

High Temperature Strength ◽

Thermal Expansion Measurement ◽

Cyclic Compression

We have suggested B2-(Pt, Ir)Ti as high temperature shape memory alloys. The phase transformation of (Pt, Ir)-50at% Ti from B2 to B19(2H) or 4H(4O) structures was investigated in our previous study. The microstructure suggested martensitic transformation. In this study, thermal expansion measurement and cyclic compression test were performed for (Pt, Ir)Ti to investigate if the shape memory effect appears. High temperature strength was also investigated because phase transformation temperature of the (Pt, Ir)Ti is above 1273 K and high strength is necessary as high temperature shape memory alloys in order to suppress dislocation motion and stabilize martenstic transformation. The potential of (Pt, Ir)Ti as high temperature shape memory alloys will be also discussed.

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