The Effect of Ti Addition on Phase Equilibria among Ni (A1), Ni3Al (L12) and Ni3V (D022) Phases

2010 ◽  
Vol 654-656 ◽  
pp. 432-435 ◽  
Author(s):  
Eiki Hayashi ◽  
Satoru Kobayashi ◽  
Kazuhisa Sato ◽  
Toyohiko J. Konno ◽  
Yasuyuki Kaneno ◽  
...  
Keyword(s):  
Binary System ◽  
Ternary System ◽  
Phase Equilibria ◽  
Eutectoid Reaction ◽  
Eds Analysis ◽  
Heat Treated ◽  
Three Phase ◽  
Rich Side ◽  
Ti Addition

The effect of Ti addition on phase equilibria among Ni (A1), Ni3Al (L12) and Ni3V (D022) phases at 950 °C was investigated through TEM/EDS analysis on heat-treated alloys. The three-phase coexisting region of A1 + L12 + D022 was found to exist around the composition of Ni-4Al-19V (at. %) in the Ni-Al-V ternary system. With addition of Ti to the ternary system the three-phase coexisting region was shifted to the Ni-rich side. Ti partitioned most into the L12 phase and least into the A1 phase. These results suggest that the addition of Ti stabilizes the L12 and D022 phases against A1 phase, and raises the temperature of eutectoid reaction in the Ni3Al-Ni3V pseudo-binary system: A1 → L12 + D022.

The Effect of Nb Addition on Phase Equilibria in the Ni-Rich Ni-Al-V Ternary System

2011 ◽  
Vol 1295 ◽  
Author(s):  
Eiki Hayashi ◽  
Satoru Kobayashi ◽  
Yasuyuki Kaneno ◽  
Takayuki Takasugi
Keyword(s):  
Ternary System ◽  
Phase Equilibria ◽  
Vertical Section ◽  
Alloying Element ◽  
Three Phase ◽  
Rich Side ◽  
Nb Addition

ABSTRACTThe effect of Nb addition on phase equilibria among Ni (A1), Ni3Al (L12) and Ni3V (D022) phases was investigated in the Ni-rich Ni-Al-V ternary system. The addition of Nb to the Ni-Al-V ternary system shifts the three-phase coexisting region of A1 + L12 + D022 towards the Ni-rich side at 950 ºC. Nb is partitioned into the D022 phase more strongly than the A1 and L12 phases. These results suggest that the addition of Nb stabilizes the D022 phase against the A1 and L12 phases in the systems. The alloying element raises the temperature of a eutectoid-like reaction (A1→L12+D022) by ~30 ºC in the vertical section of Ni-Al-V ternary system at 75 at. % Ni.

Phase Equilibria among γ-Fe, γ-Fe and Fe2Mo Phases and Stability of the Laves Phase in Fe-Mo-Ni Ternary System at Elevated Temperatures

2006 ◽  
Vol 980 ◽  
Author(s):  
Shigehiro Ishikawa ◽  
Takashi Matsuo ◽  
Masao Takeyama
Keyword(s):  
Ternary System ◽  
Phase Equilibria ◽  
Elevated Temperatures ◽  
Phase Region ◽  
Homogeneity Region ◽  
Nickel Concentration ◽  
Peritectoid Reaction ◽  
Two Phase ◽  
Three Phase ◽  
Binary Edge

AbstractPhase equilibria among the bcc Fe(α), fcc Fe(γ) and Fe2Mo(λ)_phases in Fe-Mo-Ni ternary system, particularly paying attention to the existence of the γ+λ two-phase region, have been examined at elevated temperatures below Tc (1200 K), the peritectoid reaction temperature in Fe-Mo binary system: λ?α+Fe7Mo6 (μ). At 1173 K the α+γ+μ three-phase coexisting region exists near the Fe-Mo binary edge and no λ phase region was identified. At 1073 K the λ phase in equilibrium with α and γ phases exists, although the composition homogeneity region of the ternary λ phase was limited to its binary edge toward the equi-nickel concentration direction up to about 3at % Ni. Instead, large two-phase region of γ+μ was extended along the same direction up to 20 at% Ni. The γ+λ two-phase region appears below Tc through a transition peritectoid reaction: α+μ¨γ+λ. The γ phase in equilibrium with λ phase is stable only at elevated temperatures, and it transforms martensitically to α phase during cooling. The addition of Ni stabilizes γ and μ phases against α and λ phases, thereby decreasing the relative stability of the λ phase.

Phase Equilibria between γ-Fe (A1) and Fe2Ti Laves (C14) Phases and Microstructure in Fe-Ti-Ni Ternary System at Elevated Temperatures

2007 ◽  
Vol 561-565 ◽  
pp. 435-438 ◽  
Author(s):  
Tomoaki Sugiura ◽  
Shigehiro Ishikawa ◽  
Takashi Matsuo ◽  
Masao Takeyama
Keyword(s):  
Ternary System ◽  
Phase Equilibria ◽  
Elevated Temperatures ◽  
Eutectic Reaction ◽  
Ternary Eutectic ◽  
Phase Region ◽  
Two Phase ◽  
Ni Addition ◽  
Element Addition ◽  
Rich Side

The phase equilibria among α-Fe, γ-Fe and Fe2Ti phases in Fe-Ti-Ni ternary system at 1473 K and 1373 K with Ni (γ former element) addition were examined, by paying attention to the γ+Fe2Ti two-phase region. The Fe2Ti single-phase region extends toward the equal-titanium concentration direction up to about 30 at% Ni, and the Laves phase becomes in equilibrium with γ-Fe by 12 at% Ni addition, but the γ+Fe2Ti two-phase region is limited because of the formation of liquid phase by further Ni addition at 1473 K. With decreasing temperature, a ternary eutectic reaction (L→γ-Fe+Fe2Ti+Ni3Ti) occurs, making the two-phase region wider just below the invariant reaction at 1373 K, and the region becomes narrower again by the enlargement of the three-phases region toward Fe-rich side.

Experimental Confirmation of Ni5Al3 Phase in Ni-Al Binary System by Diffusion Couple Technique

2011 ◽  
Vol 299-300 ◽  
pp. 224-227
Author(s):  
Chang Fa Li ◽  
Yu Ping Ren ◽  
Gao Wu Qin
Keyword(s):  
Binary System ◽  
Diffusion Couple ◽  
Equilibrium Phase ◽  
Solubility Range ◽  
Heat Treated ◽  
Diffusion Couple Technique ◽  
System Phase Diagram ◽  
Rich Side ◽  
System Phase ◽  
Phase Relationships

The equilibrium phase relationships and compositions of Ni - 51at.%Al/Ni - 26at.%Al diffusion couple heat treated at 650 °C for various times have been investigated by means of diffusion couple technique. Experimental results showed that Ni5Al3 phase was not only stable at 650 °C, but also had a large solubility range (45.3～40.6) at.% Al. The obtained relationships of NiAl/Ni5Al3 and Ni5Al3/Ni3Al are in accordance with the current generally accepted Ni-Al binary system phase diagram, but their composition ranges are quite different from the presently accepted one, that is, the the phase boundaries of NiAl / (Ni5Al3 + NiAl), (Ni5Al3 + NiAl) / Ni5Al3 and Ni5Al3 / (Ni3Al + Ni5Al3) significantly shift to the Al-rich side.

Phase Equilibria Among β/α/α2/γ Phases and Phase Transformations in Ti-Al-Cr System at Elevated Temperatures

MRS Advances ◽  
2019 ◽  
Vol 4 (25-26) ◽  
pp. 1471-1476
Author(s):  
Ali Shaaban ◽  
Hideki Wakabayashi ◽  
Hirotoyo Nakashima ◽  
Masao Takeyama
Keyword(s):  
Phase Equilibria ◽  
Tial Alloy ◽  
Elevated Temperatures ◽  
Volume Fraction ◽  
Eutectoid Reaction ◽  
Al Content ◽  
Three Phase ◽  
Cr Addition ◽  
Cr System ◽  
Tie Line

Abstract:Effects of Cr addition to TiAl alloy on the phase equilibria among β/α/α2/γ Phases and phase transformation pathways within the temperature range of 1523 K∼1073 K were investigated using several alloys in the composition of interest. In between 1473 K and 1373 K, The slope of β/α tie-line in the three-phase coexisting region of β+α+γ remains basically unchanged. However, this slope drastically rotates in a clockwise direction, in between 1373 K and 1273 K and below the eutectoid reaction temperature in the binary system (1400 K). This is a strong indication that α-phase exists even below the 1400 K, i.e. addition of Cr stabilizes α against α2 and the three-phase coexisting region of β+α2+γ at lower temperatures is formed through a ternary eutectoid reaction (α → β+α2+γ) with decreasing temperature. This three-phase tie-triangle moves towards lower Al content in phase diagram. This suggests that Cr addition results in increase of the volume fraction of γ-phase with decreasing temperature even in alloys with low Al content.

Assessment of the Phase Equilibria among γ-Fe/ Fe2Nb/ Ni3Nb Phases in Fe-Ni-Nb Ternary System at Elevated Temperatures

2011 ◽  
Vol 1295 ◽  
Author(s):  
Y. Hasebe ◽  
K. Hashimoto ◽  
T. Matsuo ◽  
M. Takeyama
Keyword(s):  
Isothermal Section ◽  
Ternary System ◽  
Phase Equilibria ◽  
Ternary Compound ◽  
Elevated Temperatures ◽  
Composition Range ◽  
Interaction Parameters ◽  
Three Phase ◽  
Good Agreement

ABSTRACTPhase equilibria among γ-Fe, ε-Fe2Nb Laves and δ-Ni3Nb phases in Fe-Ni-Nb ternary system at 1473 K and 1373 K were experimentally examined, and also assessed by calculation in order to calculate the phase equilibria among these phases at 973 K. A ternary compound with hP24 structure with its limited composition range of Fe-21.5Nb- (56.8-59.8) Ni exists between Fe2Nb and Ni3Nb phase regions at both temperatures. Including the hP24 phase, the calculated isotherms at both temperatures are in good agreement with experimental ones. By using the optimized interaction parameters among the three elements in each phase, the isothermal section calculated at 973 K revealed a γ-Fe+ Fe2Nb + Ni3Nb three-phase coexisting region extended to Fe-rich composition of 80 at. % Fe. This suggests a possibility to develop austenitic heatresistant steels strengthened by both intermetallics phases.

scholarly journals Solid State Phase Equilibria of an Al–Sn–Y Ternary System

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 444
Author(s):  
Wenchao Yang ◽  
Moumiao Liu ◽  
Junli Feng ◽  
Jingwu Wu ◽  
Jun Mao ◽  
...  
Keyword(s):  
Solid State ◽  
Ternary System ◽  
Phase Equilibria ◽  
Scanning Calorimetry ◽  
Two Phase ◽  
Three Phase ◽  
Binary Compounds ◽  
Lead Free Solders ◽  
Energy Disperse Spectroscopy ◽  
Phase Relationships

A complete understanding of the solid-state phase equilibria of the ternary Al–Sn–Y system is essential for the development of both Al-based structural materials and Sn-based lead-free solders. In this work, the phase relationships in the Al–Sn–Y ternary system at 473 K were investigated mainly by means of X-ray powder diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) with energy disperse spectroscopy (EDS) analysis. The existence of 12 binary compounds, namely Sn3Y, Sn5Y2, Sn2Y, Sn10Y11, Sn4Y5, Sn3Y5, AlY2, Al3Y5, Al2Y3, AlY, Al2Y and α–Al3Y, was confirmed. Controversial phases (Sn5Y2 and Al3Y5) were found in this work. This isothermal section consisted of 15 single-phase regions, 27 two-phase regions and 13 three-phase regions. No ternary compounds were found and none of the other phases in this system revealed a remarkable solid solution at 473 K.

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