Precipitation of Secondary Phase and Phase Transformation Behavior of a Solution‐Treated Ti–6Al–4V Alloy during High‐Temperature Aging

2020 ◽  
Vol 22 (5) ◽  
pp. 1901436 ◽  
Author(s):  
Y. C. Lin ◽  
Yi Tang ◽  
Yu-Qiang Jiang ◽  
Jian Chen ◽  
Dan Wang ◽  
...  
Keyword(s):  
Phase Transformation ◽  
High Temperature ◽  
Secondary Phase ◽  
Transformation Behavior ◽  
Phase Transformation Behavior ◽  
Solution Treated ◽  
High Temperature Aging ◽  
Temperature Aging

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).

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

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.

scholarly journals The influence of the heating rate of cemented constructional steels on the growth of austenitic grain in the process of high-temperature holding

2019 ◽  
Vol 63 (4) ◽  
pp. 399-406 ◽  
Author(s):  
V. A. Kukareko ◽  
A. L. Valko ◽  
A. N. Chichin
Keyword(s):  
Phase Transformation ◽  
High Temperature ◽  
Thermal Treatment ◽  
Grain Boundaries ◽  
Grain Structure ◽  
Slow Heating ◽  
Experimental Conditions ◽  
Impurity Atoms ◽  
High Temperature Aging ◽  
Temperature Aging

The influence of the heating mode of samples of constructional cemented steels 20ХН3А, 20ХГНР and 15ХГН2ТА on the value of austenite grain after high-temperature isothermal aging at 1000 °С is studied. It is shown that the heating of steels at a rate of 1.2–3.0 °C / min in the phase-transformation interval stabilizes the grain structure of the steels and leads to a slowing down of the kinetics of the growth of austenite grains during prolonged high-temperature aging, which makes it possible to increase the temperature of the chemical-thermal treatment of steels. It is concluded that the stabilization of the grain structure of steels is associated with the formation of segregation of impurity atoms and particles at grain boundaries with high-angle disorientation during slow heating, which prevents migration of grain boundaries in the process of prolonged high-temperature aging. A high-temperature chemical-thermal treatment of a batch of billets from steel 20ХН3А under experimental conditions with stepwise heating in the phase-transformation interval provided a qualitative fine-grained structure of the cemented layer.

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