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Phase equilibria of the Cr-Mo-Ru ternary system at 1100 °C and 1200 °C have been experimentally investigated using electron probe microanalyzer and x-ray diffraction. The σ-Cr2Ru forms a σ-(Mo5Ru3, Cr2Ru) continuous solid solution phase with the σ-Mo5Ru3 phase at 1200 °C, but not at 1100 °C. The BCC (Cr, Mo) continuous solid solution phase exists at both 1100 °C and 1200 °C. Based on the measured experimental results and the thermodynamic parameters of the three binary sub-systems, a set of self-consistent parameters of the Cr-Mo-Ru system was evaluated using the CALPHAD method. Several vertical sections, isothermal sections, and liquidus surface projection of the Cr-Mo-Ru ternary system were calculated in this study. The results of phase equilibrium experiments and thermodynamic calculations show that although the solid solubility of the σ phase in the Cr-Mo and Mo-Ru binary systems is relatively small, it is exceptionally large in the Cr-Mo-Ru ternary system. The current obtained thermodynamic parameters of the Cr-Mo-Ru ternary system can provide the essential information and support for the theoretical guidance on the design of the Ni-based multi-component superalloys. [ABSTRACT FROM AUTHOR]

In this work, two isothermal sections of the Co-Ta-Si ternary system at 900 °C and 1100 °C are constructed in the whole composition range via phase equilibrium determination with the help of electron probe microanalysis (EPMA) and X-ray diffraction (XRD) techniques. Firstly, several reported ternary phases G (Co16Ta6Si7), G″ (Co4TaSi3), E (CoTaSi), L (Co3Ta2Si) and V (Co4Ta4Si7) are all re-confirmed again. The G″ phase is found to be a kind of high-temperature compound, which is unstable at less than 1100 °C. Additionally, the L phase with a large composition range (Co32–62Ta26–36Si10–30) crystallizes with a hexagonal crystal structure (space group: P63/mmc, C14), which is the same as that of the binary high-temperature λ1-Co2Ta phase. It can be reasonably speculated that the ternary L phase results from the stabilization toward low-temperature of the binary λ1-Co2Ta through adding Si. Secondly, the binary CoTa2 and SiTa2 phases are found to form a continuous solid solution phase (Co, Si)Ta2 with a body-centered tetragonal structure. Thirdly, the elemental Si shows a large solid solubility for Co-Ta binary compounds while the Ta and Co are hardly dissolved in Co-Si and Ta-Si binary phases, respectively. [ABSTRACT FROM AUTHOR]

In this study, the isothermal sections of the Co-Nb-Re ternary system at 1200, and 1300 °C have been experimentally determined combining the means of electron probe microanalysis (EPMA) and x-ray diffraction (XRD). The obtained experimental results showed that: (1) The Laves phase of λ3-Co2Nb (C36) was stable at 1300 °C. The temperature was beyond its stability limit in Co-Nb binary system. (2) The solubility of Re in the λ3 phase was so large that the nearest λ2-Co2Nb (C15) phase was essentially surrounded. (3) The solubility of Re in the μ-Co7Nb6 phase was 34.0 at.% at 1200 °C and 35.2 at.% at 1300 °C, respectively. (4) The liquid phase existed at 1300 °C dissolving about 4.0 at.% Re, but it was absent at 1200 °C. (5) The solid solution phase of (εCo, Re) extended from Re-rich to Co-rich side. [ABSTRACT FROM AUTHOR]

The phase equilibria of the Co-Ti-Ru ternary system at 1000, 1100, and 1200 °C were studied using the electron probe microanalyzer and x-ray diffraction. The results show that: (1) no ternary compound exists in the isothermal sections from 1000 to 1200 °C; (2) the phases of CoTi and TiRu form the continuous solid solution phase (Co,Ru)Ti; (3) the solubility of Ru in the Co3Ti phase is less than 5 at.% at isothermal sections 1000-1100 °C. These experimental results will provide useful information for the foundation for alloy design and the supplement for thermodynamic databases. [ABSTRACT FROM AUTHOR]

Author names and affiliations should be as follows: Yanqing Zhang1, 2; Xiaodong Chen1, 2; Hui Ren1, 2; Hu Liu1, 2; Shuiyuan Yang1, 2; Yong Lu1, 2*; Jiajia Han1, 2; Cuiping Wang1, 2*; Xingjun Liu1, 3 1 College of Materials and Fujian Key Laboratory of Surface and Interface Engineering for High Performance Materials, Xiamen University, Xiamen 361005, P. R. China. 2 Xiamen Key Laboratory of High Performance Metals and Materials, Xiamen University, Xiamen 361005, P. R. China. [Extracted from the article]

The phase equilibria of the Mg–Pb–Zn ternary system were investigated using electron probe microanalysis (EPMA), back scattered electron (BSE) imaging and X-ray diffraction (XRD) methods. Three isothermal sections of the Mg–Pb–Zn ternary system at 200 °C, 300 °C and 400 °C were experimentally established. The phase equilibria of Mg–Pb binary and Mg–Pb–Zn ternary system were thermodynamically assessed by using CALPHAD (Calculation of Phase Diagrams) method on the basis of the presently determined experimental data. A consistent set of thermodynamic parameters has been derived for describing the Gibbs free energies of each solution phase and intermetallic compound in the Mg–Pb and Mg–Pb–Zn systems. The calculated phase diagrams and thermodynamic properties in the Mg–Pb and Mg–Pb–Zn systems are in good agreement with experimental data. [ABSTRACT FROM AUTHOR]

The phase equilibria of the Sn-Zn-Sb ternary system at 400 and 500 °C were experimentally determined by electron probe microanalyzer, x-ray diffraction and differential scanning calorimetry. In this study, the ternary compound of (Zn,Sn)Sb is confirmed at 400 and 500 °C. Additionally, a liquid phase region is found at 400 °C with composition ranges of 9.09-12.86 at.% Zn and 31.47-34.22 at.% Sn, which becomes a prolongation of the main liquid as the temperature is raised to 500 °C. [ABSTRACT FROM AUTHOR]

The phase equilibria of the Bi-Cu-Zn ternary system has been firstly and comprehensively investigated by electron probe microanalyzer (EPMA) with equilibrated alloys. Two isothermal sections of the Bi-Cu-Zn ternary system at 500 and 650 °C were determined. Based on the experimental data of phase equilibria, the Bi-Cu-Zn ternary system was also thermodynamically optimized using the Calculation of Phase Diagrams (CALPHAD) method. The experimental result shows that Bi is almost insoluble in the Cu-Zn binary compounds and (Cu) phase. It is found that the critical temperatures of the miscibility gaps in the Bi-Cu and Bi-Zn binary systems gradually increase with the increasing of the third element Zn or Cu additions. Moreover, the composition range of the liquid miscibility gap gradually reduces with the temperature increasing. [ABSTRACT FROM AUTHOR]

Highlights: [•] Three isothermal sections of the Fe–Nb–Si system were experimentally determined. [•] Some different phase relationships are confirmed in this work. [•] The solubility of Si in the εNbFe2 phase is about 27.5at.%, remaining unchanged with the temperature range from 1200°C to 1000°C. [•] The solubility of Si in the μFeNb phase decreases from 14.7at.% to 10.0at.% with decrease of temperature from 1200°C to 1000°C. [ABSTRACT FROM AUTHOR]

Phase equilibria of the Ni-Cr-Si ternary system at 1000 and 1100 °C have been experimentally investigated by means of electron probe microanalyzer (EPMA) and x-ray diffraction (XRD) analysis on the equilibrated alloys. In the present work, the existence of the ternary compounds of σ (CrNiSi), π (CrNiSi), τ (CrNiSi) and τ (CrNiSi), at both 1000 and 1100 °C is confirmed. The binary γ (NiSi), δ (NiSi), and CrSi phases exhibit a considerable solubility of a third element. Additionally, a liquid phase region is found at 1100 °C in the ranges of 15.5-21.3 at.% Cr and 22.1-25.1 at.% Si. [ABSTRACT FROM AUTHOR]

Phase equilibria in the Co-Cr-Nb ternary system were experimentally investigated by using back-scattered scanning electron microscopy, electron probe microanalysis, composition mapping and x-ray diffraction on equilibrated alloys. In this study, isothermal sections of the Co-Cr-Nb ternary system at 1000, 1100 and 1200 °C were determined. The intermetallic compounds CoNb and CoCrNb, together with their single phase regions were determined on all three isotherms, as well as three tie triangles involving the (Nb) + CoNb + CoCrNb, (αCr) + σ + CoCrNb and (αCo) + σ + CoCrNb phases. The current diagrams differed significantly from a previous isotherm reported at 1000 °C. The newly determined phase equilibria in the Co-Cr-Nb system may provide useful information for perpendicular magnetic recording materials and high-temperature alloys. [ABSTRACT FROM AUTHOR]

Abstract: In this study, small Ta was added into two-phase Ni53Mn22Co6Ga19 high-temperature shape memory alloy to refine grain for further improving the ductility and shape memory effect of the alloy. It is found that small Ta addition results in the refinement of grain size. This change simultaneously improve the tensile ductility and shape memory effect of the alloy, being up to 11% and 3.3% at Ta=0.2at.%, respectively. With further increasing Ta addition to 0.4at.%, the ordered γ′ phase is present, and it tends to wrap γ phase and segregates martensite and γ phase, which lead to a decrease in the ductility of the alloy at Ta=0.4at.%. The obtained results may provide useful information on improving the ductility and shape memory effect for some other type of two-phase shape memory alloys. [Copyright &y& Elsevier]

The phase equilibria of the Co-Ti-Ta ternary system at 1000 °C, 1100 °C, and 1200 °C were experimentally investigated using an electron probe microanalyzer and X-ray diffraction. Experimental results show that: (1) No ternary compound exists in the studied isothermal sections; (2) the β(Ti) and β(Ta) phases form the continuous solid solution β(Ti,Ta) in the Ti-Ta side; (3) the solubility of Ta in the (αCo) is less than 5%; (4) the phases of Co2Ti(h) and γ-Co2Ta, Co2Ti(c) and β-Co2Ta form the continuous solid solutions Co2(Ta,Ti)(h) and Co2(Ta,Ti)(c), respectively. [ABSTRACT FROM AUTHOR]

In this study, the isothermal sections of the Co-Re-Ta ternary system at 1100, 1200, and 1300 °C have been experimentally investigated by means of electron probe microanalysis and X-ray diffraction. The results indicated the following: (1) The solid solubilities of the λ3, (εCo, Re), χ-Re7Ta3, and bcc-(Ta) phases were large and changed very little from 1100 to 1300 °C; (2) more interestingly, the λ2 phase, with a very limited solubility of Re, was surrounded by the λ3 phase; (3) the solubility of Re for the μ-Co6Ta7 phase increased slowly from 1100 to 1300 °C. These experimental results will be useful for Co-based high-temperature alloys, especially as a supplement for thermodynamic databases. [ABSTRACT FROM AUTHOR]

Two isothermal sections of the Ni-V-Ta ternary system at 1200 °C and 1000 °C have been experimentally established using X-ray diffraction, electron probe microanalysis, energy dispersive spectroscopy, and differential scanning calorimeter with equilibrated key alloys. The equilibrium composition of each phase is measured by electron probe microanalysis and energy dispersive spectroscopy. The results indicate that: (1) nine three-phase and eight three-phase regions were confirmed in the isothermal section at 1200 °C and 1000 °C, respectively; (2) the C14 phase with a large solubility of about 51.2 at. % Ni was observed at 1200 °C, while it forms a single-phase region at 1000 °C; (3) a small liquid region was confirmed at 1200 °C, but disappeared at 1000 °C. [ABSTRACT FROM AUTHOR]

A 1000 °C isothermal phase diagram in the total composition range of the Fe-Co-Si ternary system is constructed featuring the interconnected ε-(Fe,Co)Si, large bcc-structure (αFe), and fcc-structure (γFe,αCo) phases. In addition, a vertical magnetic plus ordering transition phase diagram of Fe 80- x Co x Si 20 alloys is also constructed. It is shown that the magnetic transition (D0 3 ferro./para. ) temperature increases with the Co concentration and reaches a maximum value (845 °C) at 50 at. % Co in the investigated Fe 80- x Co x Si 20 alloys. Meanwhile, the B2/D0 3 ordering transition temperature versus Co content dependence exhibits an initial slight rise followed by a gradual decrease to ∼67 at. % Co. Furthermore, a fcc/bcc martensitic transformation was revealed in several Co-rich ternary alloys under study. The resulting lath martensitic microstructures of the studied alloys include numerous twins and dislocations defects, revealing a similarity with the FeNi-based alloy system. [ABSTRACT FROM AUTHOR]

Highlights: [•] Three isothermal sections of the Cu–Ni–Si system have been investigated. [•] The ternary compound τ1 and the liquid phase are confirmed at 1073K. [•] The γ (Cu5Si) and θ (Ni2Si) phases can be stabilized at higher or lower temperatures. [ABSTRACT FROM AUTHOR]

Abstract: The phase equilibria in the Co–W–Nb ternary system were experimentally investigated using optical microscopy, electron probe microanalysis and X-ray diffraction on equilibrated alloys. In this study, isothermal sections of the Co–W–Nb ternary system at 1000 °C, 1100 °C and 1200 °C were determined, and no ternary compound was found. Further results show that a Nb-stabilized Co3W phase is stable at 1100 °C, but not at 1200 °C in the Co–W–Nb system. The α Co2Nb and γ Co2Nb phases were identified to possess large solubility of W in the present study. The newly determined phase equilibria of the Co–W–Nb in the present study will provide useful information for the development of cemented carbides and high-temperature structural materials. [Copyright &y& Elsevier]

The phase equilibria at 1000 °C of the Co-V-Ga ternary system and composition dependence of martensitic transformation characteristics in Co 2 VGa Heusler alloys are investigated. Firstly, the results show that six three-phase regions and three ternary compounds are identified in the isothermal section. The CoVGa compound is discovered with a composition range of 43.0–46.2 at.% V and 27.3–31.4 at.% Ga. Secondly, according to the obtained phase equilibria, the martensitic transformation characteristics depending on composition for those alloys that locate the Co 2 VGa Heusler phase region are investigated. The results confirm that the Co 2 VGa Heusler phase exists in a wide composition range (about 39.7–66.5 at.% Co, 4.8–40.0 at.% V, and 15.0–31.2 at.% Ga). Furthermore, the critical compositions with the martensitic transformation temperature close to room temperature are determined, in which those alloys (50.8–58.5 at.% Co, 20.2–33.0 at.% V, and 15.2–21.5 at.% Ga) show the martensite structure at room temperature. Thirdly, based on the phase equilibria and the composition dependence of martensitic transformation characteristics, a Co 55 V 24 Ga 21 shape memory alloy is designed. Its microstructure, reversible martensitic transformation, and shape memory effect are investigated. Full shape recovery of about 2.6% is obtained. The present obtained results may provide useful information for composition designation and the estimation of martensitic transformation temperatures of Co-V-Ga Heusler shape memory alloys. • The phase equilibria of the Co–V-Ga ternary system is determined. • The CoVGa compound is discovered firstly at 1000 °C. • The Co 2 VGa Heusler phase exists a wide composition region. • The composition range of Co 2 VGa phase with the M s higher than RT is determined. • The full recovery strain of 2.6% is obtained in Co 55 V 24 Ga 21 alloy. [ABSTRACT FROM AUTHOR]

Phase equilibria of the Al-Co-Ta ternary system over the whole composition range at 1200 °C and 1300 °C were experimentally determined from the equilibrated alloys using electron probe microanalysis, scanning electron microscopy, and X-ray diffraction. The measured results indicate that, at 1200 °C, the addition of Al can stabilize the λ 1 -Co 2 Ta phase (Laves C14-type), which is absent in binary system, and forms a broad phase region parallel to the Al-Co axis in the Al-Co-Ta ternary isothermal sections. The ternary compound of the Heusler phase AlCo 2 Ta (L2 1 -type) was confirmed at both investigated isothermal sections with the composition range about 49.7–55.7 at% Co and 14.7–23.6 at% Ta. In addition, a large solubility of Al was identified in the μ-Co 6 Ta 7 phase. Based on the experimental results, the published data of the Al-Co and Al-Ta binary systems, and the reassessed Co-Ta parameters from the current work, a thermodynamic assessment of the Al-Co-Ta system was undertaken using the CALPHAD technique. A set of reliable thermodynamic parameters for the Al-Co-Ta system was obtained with a satisfactory agreement with the experimental data. The calculated liquidus projection and invariant reaction scheme in the Al-Co-Ta ternary system were presented. The present work can provide essential experimental and thermodynamic data for the establishment of the Co-based alloy database. • The isothermal sections of the Al-Co-Ta ternary system at 1200 °C and 1300 °C were experimentally determined. • The addition of Al stabilizes the λ 1 -Co 2 Ta phase (Laves C14-type) at 1200 °C. • A large solubility of Al was identified in the μ-Co 6 Ta 7 phase. • The composition range of ternary compound AlCo 2 Ta (L2 1 -type) was defined at 1200 °C and 1300 °C isothermal sections. • The Co-Ta binary and the Al-Co-Ta ternary systems were thermodynamically assessed using CALPHAD technology. [ABSTRACT FROM AUTHOR]

• The isothermal sections at 1300, 1100 and 900 °C were experimentally determined. • A new ternary compound (named F) was detected within the compositional range of Ni 23–25 Ta 39–40 Si 35–38. • The range of the ternary Laves phase (C14) was revised to be Ni 39–54 Ta 26–33 Si 13–27. • The binary NiTa 2 and Ta 2 Si phases form a continuous solid solution (Ni, Si)Ta 2. Three isothermal sections of the Ni-Ta-Si ternary system at 1300, 1100 and 900 °C were constructed in the whole composition range and analysed using electron probe microanalysis (EPMA), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. In addition to the known ternary G, E, H and C14 phases, a new compound with the composition of Ni 23–25 Ta 39–40 Si 35–38 was detected for the first time, herein designated as the F phase. Furthermore, the continuous (Ni, Si)Ta 2 phase was found to be stable and the composition range of the ternary C14 Laves phase was revised to be Ni 39–54 Ta 26–33 Si 13–27. The newly determined phase equilibria in the Ni-Ta-Si ternary system can be useful in guiding alloying strategies or composition design of Ni-based superalloys. [ABSTRACT FROM AUTHOR]