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

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.

2006 ◽  
Vol 980 ◽  
Author(s):  
Shigehiro Ishikawa ◽  
Takashi Matsuo ◽  
Masao Takeyama

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.


2013 ◽  
Vol 815 ◽  
pp. 3-7
Author(s):  
Shi Ping Guo ◽  
Wei He ◽  
Yun Hong Zhao ◽  
Ling Min Zeng

The isothermal sections of the Er-Cu-V and Dy-Cu-V ternary systems at 773K were investigated by experiments. The isothermal section of Er-Cu-V consists of 8 single-phase regions, 13 two-phase regions and 6 three-phase regions. The binary compounds ErCu5, ErCu2, ErCu, Er2Cu9and Er2Cu7were observed at 773K. The isothermal section of Dy-Cu-V consists of 7 single-phase regions, 11 two-phase regions and 5 three-phase regions. The binary compounds DyCu5, DyCu2, DyCu and Dy2Cu9were confirmed at 773K. No ternary compound was found in the two sections. There is no solubility of V in the Er-Cu and Dy-Cu binary compounds observed.


2011 ◽  
Vol 314-316 ◽  
pp. 1262-1267 ◽  
Author(s):  
Xue Hui An ◽  
Qian Li ◽  
Jie Yu Zhang

The isothermal section at 573 K of the Ni-Cu-La system was experimentally validated as well as the Mg-La-Cu system was thermodynamically evaluated. Four sample alloys in the Ni-Cu-La system were prepared and analyzed by ICP, XRD and BSE/EDS. All the experimental results were compared favorably with the calculated phase relationships. For the Mg-La-Cu ternary system, the isothermal section at 673 K was assessed on the basis of the available results in literatures, which showed a good agreement with the experimental data. Based on the thermodynamic models and parameters of the six binaries and four ternaries, the Mg-Ni-La-Cu system was finally modeled. The non-equilibrium solidification path La0.7Mg0.3Ni2.8-xCux (x=0-0.4) and the vertical section of LaNi5-Mg2Cu were calculated and analyzed from the viewpoint of hydrogen storage alloys design.


2016 ◽  
Vol 697 ◽  
pp. 565-571 ◽  
Author(s):  
Rui Zhang ◽  
Pekka Taskinen

Phase equilibria of the BaO-SiO2-Al2O3 ternary system was experimentally investigated using a quenching technique and analyzed by Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Analysis (EDS) and X-ray Powder Diffraction (XRD). A ternary compound was confirmed in the present work. The liquidus composition in equilibrium with the ternary compound at 1500 °C were quantified. The isothermal sections of the BaO-SiO2-Al2O3 ternary system at 1400 °C, 1500 °C, 1600 °C, and 1700 °C were calculated. Based on the data acquired, the isothermal section at 1500 °C was constructed.


2019 ◽  
Vol 40 (4) ◽  
pp. 570-582 ◽  
Author(s):  
Shuntaro Ida ◽  
Ryosuke Yamagata ◽  
Hirotoyo Nakashima ◽  
Satoru Kobayashi ◽  
Masao Takeyama

2004 ◽  
Vol 842 ◽  
Author(s):  
Masao Takeyama ◽  
Nobuyuki Gomi ◽  
Sumio Morita ◽  
Takashi Matsuo

ABSTRACTPhase equilibria in Fe-Ni-Nb ternary system at elevated temperatures have been examined, in order to identify the two-phase region of γ-Fe (austenite) and ε-Fe2Nb (C14). The ε single phase region exists in the range of 27.5 to 35.5 at.% Nb in the Fe-Nb binary system, and it extends toward the equi-niobium concentration direction up to 44 at.% Ni in the ternary system at 1473 K, indicating that more than half of the Fe atoms in Fe2Nb can be replaced with Ni. Thus, the γ+ε two-phase region exists extensively, and the solubility of Nb in γ phase increases from 1.5 to 6.0 at.% with increase in Ni content. The lattice parameters of a and c in the C14 Laves phase decrease with increasing Ni content. The change in a axis is in good agreement with calculation based on Vegard's law, whereas that of c axis is much larger than the calculated value. The result suggests that atomic size effect is responsible for a-axis change and the binding energy is dominant factor for the c-axis change. To extend these findings to development of new class of austenitic steels strengthened by Laves phase, an attempt has been made to control the c/a ratio by alloying. The addition of Cr is effective to make the c/a ratio close to the cubic symmetry value (1.633).


2010 ◽  
Vol 654-656 ◽  
pp. 432-435 ◽  
Author(s):  
Eiki Hayashi ◽  
Satoru Kobayashi ◽  
Kazuhisa Sato ◽  
Toyohiko J. Konno ◽  
Yasuyuki Kaneno ◽  
...  

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.


2011 ◽  
Vol 689 ◽  
pp. 355-360
Author(s):  
Qiu Guo Xiao ◽  
Gang Cheng Ding ◽  
Tang Zhong Long ◽  
Shao Hua Shen

This paper has put forward a high-temperature quantitative X-ray powder diffraction analysis method for the determination of an isothermal section of a ternary system in comparison with a conventional method. In a three-phase region of the isothermal section at 1150 °C of Cu2O(CuO)-Al2O3-SiO2 pseudo-ternary system, the compositions of the solid phase points of three system points are determined according to the quantitative analysis of the crystalline phases in the samples carried out by Rietveld method. Then the liquid phase point of the three-phase region is determined according to the crosspoints of the tie lines of every pair of system point and solid phase point. The precisions of the analytical results have reached to be 0.1 ~ 5.0 %. By comparison, a good result is obtained for the determination of the liquid phase point of the three-phase region in the isothermal section at 1150 °C when the analytical results of high-temperature RQA analysis are used in determination of the isothermal section of the pseudo-ternary system.


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