Zr Ternary System Research Articles

Isothermal section of the Al–Dy–Zr ternary system at 773 K

The phase relations in the Al–Dy–Zr ternary system at 773 K have been investigated by X-ray powder diffraction (XRD) and scanning electron microscope (SEM) with energy disperse X-ray spectroscopy (EDX) in backscattered electron imaging (BSE) modes. The isothermal section at this temperature is featured with 17 single-phase regions, 32 two-phase regions and 16 three-phase regions. Besides, the ternary compound Al 30Dy 7Zr 3 has been confirmed to be existed. The maximum solid solubility of Zr in AlDy 2, Al 2Dy 3, AlDy, Al 2Dy and Al 3Dy at 773 K is determined to be 11.5 at.%, 7.8 at.%, 2.4 at.%, 22.5 at.% and 2.5 at.%, respectively.

Experimental determination of the phase equilibria in the Co–Fe–Zr ternary system

The phase equilibria in the Co–Fe–Zr ternary system were investigated by means of optical microscopy (OM), electron probe microanalysis (EPMA), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) on equilibrated ternary alloys. Four isothermal sections of the Co–Fe–Zr ternary system at 1300 °C, 1200 °C, 1100 °C and 1000 °C were experimentally established. The experimental results indicate that (1) no ternary compound was found in this system; (2) the solubility of Fe in the liquid phase of the Co-rich corner at 1300 °C is extremely large; (3) the liquid phase in the Zr-rich corner and the (Co,Fe) 2Zr phase form the continuous solid solutions from the Co–Zr side to the Fe–Zr side; (4) the solubility of Zr in the fcc (Co, Fe) phase is extremely small.

Computational study of atomic mobility for the bcc phase of the U–Pu–Zr ternary system

Experimental diffusion data in literature has been evaluated to assess the atomic mobility for the bcc phase in the U–Pu–Zr system by means of the DICTRA-type (Diffusion Controlled TRAnsformation) phenomenological treatment. The developed mobility database has been validated by comprehensive comparisons made between the experimental and calculated diffusion coefficients, as well as other interesting details resulting from interdiffusion, e.g. the concentration profile and the diffusion path of diffusion couples.

The phase equilibria in the Pr–Si–Zr ternary system at 773 K

The phase relationships in the Pr–Si–Zr ternary system at 773 K have been investigated mainly by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analysis (DTA). 9 binary compounds, i.e. Pr 5Si 3, Pr 5Si 4, PrSi, PrSi 2, ZrSi 2, ZrSi, Zr 5Si 4, Zr 3Si 2 and Zr 2Si were confirmed. The isothermal section of the Pr–Si–Zr ternary system at 773 K consists of 12 single-phase regions, 21 two-phase regions and 10 three-phase regions. None of the intermediate compound phases in this system exhibits a remarkable solid solution range at 773 K.

Thermodynamic analysis of the Al–Cu–Zr bulk metallic glass system

As an essential constitution of either Cu- or Zr-based bulk metallic glass alloys, the Al–Cu–Zr ternary system has aroused a great attention for decades. Since the three constituent binary systems, Al–Cu, Al–Zr and Cu–Zr, have been optimized previously, the focus of this work was only given to the Al–Cu–Zr ternary system. Based on the experimental enthalpies of mixing of ternary liquid and undercooled liquid alloys as well as the evaluated isothermal sections, the Al–Cu–Zr ternary system has been assessed using the CALPHAD method. Most of the calculated results show good agreement with the experimental thermodynamic data and the reported phase diagrams. By employing the driving force criterion with the present thermodynamic description, the observed glass-forming abilities in the Al–Cu–Zr system can be accounted for satisfactorily.

An experimental study of the Fe–Sn–Zr ternary system at 900 °C

The partial isothermal section of the Fe–Sn–Zr system at 900 °C reported in Ref. [7] was completed. As compared with this section, three new ternary compounds were evidenced (Y, C36 and Fe6Sn6Zr), one compound previously reported with a homogeneity domain (X) was shown to consist in fact of two separate compounds with close compositions (X′ and X″). The crystal structure of the previously reported N phase was determined ab initio from powder diffraction data.

Application of Response Surface Method using Rapid Screening, Support Vector Machine, and Multiple Regression on the Acidity and Activity of Si−Al−Zr Ternary Oxide

To study the synergistic effect on the acidity and activity of Si-Al-Zr ternary oxide system, the mixture design of experiments was applied to prepare the ternary oxides by a sol-gel method, and rapid screening on dehydration of isopropanol and Friedel-Crafts reaction was conducted to determine the activities. These activities, amount of acid site determined by pyridine pulse, and specific surface area, were correlated with the oxide composition by means of support vector machine. Clear synergy among the Si-Al-Zr was observed on the acidic character and the surface area, whereas no synergy between Al-Zr was observed on the catalytic activities. Multiple regression was then conducted to find a relationship between the activities and the characters. The term of Si molar fraction in the oxide was essential for good regression, and acid strength determined by peak temperature of NH(3) desorption was related to the Si fraction. Thus, simple and rapid technique for activity test and characterization can be integrated by means of support vector machine and multiple regression, and some insights of the active site were obtained.

Phase equilibria of the Al–Pr–Zr ternary system at 773 K

The phase equilibria of the Al–Pr–Zr ternary system at 773 K have been investigated mainly by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analysis (DTA). The 14 binary compounds, i.e. AlZr 3, AlZr 2, Al 2Zr 3, Al 3Zr 4, AlZr, Al 3Zr 2, Al 2Zr, Al 3Zr, α-Al 11Pr 3, Al 3Pr, Al 2Pr, β-AlPr, AlPr 2 and β-AlPr 3 were confirmed. No binary compound was found in the Pr–Zr binary system. The result shows that the isothermal section of the Al–Pr–Zr ternary system at 773 K consists of 17 single-phase regions, 31 two-phase regions and 15 three-phase regions. All the intermediate compounds phases in this system have not a remarkable solid solution at 773 K. No ternary compound is found in this work.

Phase equilibria of the Co–Ni–Zr system at 1198 K

The isothermal section of the phase diagram of the Co–Ni–Zr ternary system at 1198 K has been investigated by means of diffusion triple and electron microprobe analysis. This isothermal section consists of six three-phase regions. The homogeneity ranges of Co 23Zr 6, Co 2Zr, CoZr, Ni 5Zr, Ni 7Zr 2 and NiZr are about 16.7%–18.8 at.%Zr, 28.6%–32.3 at.%Zr, 49.2%–51.7 at.%Zr, 16.0%–18.7 at.%Zr, 22.3%–24.1 at.%Zr and 49.8%–52.1 at.%Zr, respectively; CoZr 2 and NiZr 2 are nearly linear compounds. The largest solubilities of Ni in Co 23Zr 6, Co 2Zr and CoZr are about 4.9 at.%Ni, 5.4 at.%Ni and 4.5 at.%Ni, respectively. CoZr 2 and NiZr 2 form a continuous solid solution (Co,Ni)Zr 2. No ternary compound is observed.

Phase equilibria in the Fe–Ti–Zr system at 1023K

Abstract Phase relations for Fe–Ti–Zr ternary system at 1023 K have been investigated by means of diffusion triple together with electron probe microanalysis technique, a series of tie-lines and tie-triangles have been determined and the isothermal section at 1023 K has been established, and seven three-phase fields have been figured out. It was found that all of the Fe–Zr and Fe–Ti binary phases show large ternary solubility, and Zr and Ti can substitute for each other to a certain degree. The largest solid solubility of Ti in Fe 2 Zr and in FeZr 3 is about 8.5 at.% Ti and 35.7 at.% Ti, and of Zr in Fe 2 Ti and FeTi is about 5.6 at.% Zr and 6.3 at.% Zr, respectively. The solubility range of Fe 2 Ti, FeTi, Fe 2 Zr and FeZr 3 is 64.9–72.7 at.% Fe, 46.6–49.1 at.% Fe, 65.8–71.7 at.% Fe and 20.9–24.3 at.% Fe, respectively. No ternary compound was found.

Thermodynamic assessment of the Fe–Al–Zr phase diagram

The thermodynamic assessment of the Fe–Al–Zr ternary system was performed using the CALPHAD technique. The four published isothermal sections at 1073, 1173, 1273 and 1423 K, together with the proposed liquidus surface and the corresponding invariant reaction scheme, were taken into account. The reliability of the previous binary assessments was checked for the systems of interest, namely, for the Fe–Zr, Zr–Al and Fe–Al systems. Reassessment of the C15 Laves phase of the Fe–Zr system has been done to obtain a better description of the phases in the ternary system. The solution phases, including liquid, α -Fe, γ -Fe, α -Zr, β -Zr and γ -Al, were modelled as substitutional solutions, while the new ternary phases ( τ 1 , τ 2 and τ 3 ) were modelled as linear and stoichiometric compounds, respectively. The C14 and C15 Laves phases have been assessed using a two-sublattice model. Any ternary solubility of the other binary phases was not taken into account in the ternary assessment. The liquidus projection and several isothermal sections were calculated, and they agreed reasonably well with the reported experimental data.

The isothermal section of the Ti–Co–Zr ternary system at 773 K

The phase equilibria of the Ti–Co–Zr ternary system at 773 K have been investigated mainly by powder X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive analysis (EDX). The isothermal section consists of 16 single-phase regions, 31 two-phase regions and 16 three-phase regions. There are 11 binary compounds, i.e. CoZr 3, CoZr 2, CoZr, Co 2Zr, Co 23Zr 6, Co 11Zr 2, TiCo 3, h-TiCo 2, c-TiCo 2, TiCo, Ti 2Co in the system. The existence of two ternary compounds Co 10Ti 7Zr 3 and Co 66Ti 17Zr 17 has been confirmed at 773 K. Co 2Zr, CoZr 3 and TiCo have a range of homogeneity. The solubilities of Ti in CoZr was determined to be up to 8.1 at.% Ti.

Thermodynamic modeling of the Th–U, Th–Zr and Th–U–Zr systems

The thermodynamic assessments of the Th–U, Th–Zr binary and Th–U–Zr ternary systems were carried out by using the CALPHAD ( Calculation of Phase Diagrams) method on the basis of the experimental data including phase equilibria and thermodynamic properties. The Gibbs free energies of the liquid, bcc, fcc, hcp, αU and βU phases were described by the subregular solution model with the Redlich–Kister equation, and that of the δ phase in the Th–U–Zr ternary system was described by the sublattice model. The thermodynamic parameters of each phase in the Th–U–Zr system were also evaluated by combining the experimental data of the phase equilibria with the parameters in three binary systems. The calculated phase equilibria are in good agreement with the experimental data.

A Study of the Isothermal Section of the Cu—Ag—Zr Ternary System at 1023 K by Diffusion Triple Technique.

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The isothermal section of the Cu–Ti–Zr system at 1023 K measured with diffusion-triple approach

The isothermal section of the Cu–Ti–Zr ternary system at 1023 K has been constructed by using diffusion triple together with electron probe microanalysis, which consists of 15 single-phase fields, 25 two-phase fields and 13 three-phase fields. A ternary phase, Cu 2TiZr, is confirmed. Most of the Cu–Ti and Cu–Zr binary phases show large ternary solubility, in which Zr and Ti can substitute for each other to a certain degree. In addition, at 1023 K, the CuTi 2 and CuZr 2 phase can form a continuous solution phase in the Cu–Ti–Zr ternary system.

A study of the isothermal section of the Cu–Ag–Zr ternary system at 1023 K by diffusion triple technique

The phase relations in the Cu–Ag–Zr ternary system at 1023 K have been studied by using diffusion triple together with EPMA technique. The tie-lines for two-phase equilibrium were drawn and tie-triangles for three-phase equilibrium were estimated. Then, the isothermal section at 1023 K has been established, which consists of 9 three-phase fields. A ternary phase was confirmed, whose composition is about Cu 67.7–75.2Ag 9.2–15.4Zr 15.2–17.2. The AgZr 2 and CuZr 2 were found to form a continuous solid solution, which can be represented as (Ag, Cu)Zr 2.

Partial Phase Diagram of the Au—Ag—Zr Ternary System

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Partial phase diagram of the Au–Ag–Zr ternary system

On the basis of Au–Ag, Au–Zr and Ag–Zr binary phase diagrams, the 700 °C isothermal section of the gold–silver-rich field in the Au–Ag–Zr ternary system was established by X-ray diffraction analysis, electron probe microanalyses (EPMA) and optical microscopy. It is found that there is the long single-phase region, Au(Ag) or Ag(Au), along the Au–Ag binary isomorphous system on the gold–silver-rich side of the 700 °C isothermal section. The solid solubility of Zr in Au(Ag) decreases with the silver content of Au(Ag). It is confirmed that the partial 700 °C isothermal section consist of five single-phase regions: solid solution Au(Ag) or Ag(Au), Au 4Zr, Au 3Zr, Au 2Zr and AgZr; seven two-phase regions: Au 4Zr + Au(Ag), Au 3Zr + Au(Ag), Au 2Zr + Au(Ag), Au 4Zr + Au 3Zr, Au 3Zr + Au 2Zr, AgZr + Au(Ag) and AgZr + Au 2Zr; three three-phase regions: Au 4Zr + Au 3Zr + Au(Ag), Au 3Zr + Au 2Zr + Au(Ag) and Au 2Zr + AgZr + Au(Ag). No new ternary compound is formed in the gold–silver-rich field of the Au–Ag–Zr ternary system.

Thermodynamic Approach for Predicting the Glass Forming Ability of Amorphous Alloys

Abstract A new thermodynamic calculation scheme has been proposed to estimate the composition dependency of glass forming ability in multicomponent alloy systems. The driving forces of formation of crystalline phases were calculated under metastable supercooled liquid states, using a CALPHAD thermodynamic calculation technique. The composition which shows a local minimum of the driving forces was selected as a composition with the highest glass forming ability in the given alloy system. This method was applied to the Cu–Ti–Zr ternary system. The experimentally reported composition dependency of the glass forming ability could be successfully explained. The driving force criterion can be used as a simple calculation scheme to search a multicomponent alloy composition with high glass forming ability for the development of bulk amorphous alloys.

Progress in the Thermodynamic Modeling of the O—U—Zr Ternary System

AbstractFor Abstract see ChemInform Abstract in Full Text.