Phase Equilibria in the Al-Zr-Nd System at 773 K

The isothermal section of the phase diagram of the Al-Zr-Nd ternary system at 773 K has been investigated by means of x-ray powder diffraction (XRD), scanning electron microscopy (SEM) and optical microscopy (OM) for the first time. The existences of 14 binary compounds i.e. Al₃Zr, Al₂Zr, Al₃Zr₂, AlZr, Al₃Zr₄, Al₂Zr₃, AlZr₂, AlZr₃, α-Al₁₁Nd₃, Al₃Nd, Al₂Nd, AlNd, AlNd₂ and AlNd₃ were confirmed. The isothermal section consists of 17 single-phase regions, 31 binary-phase regions and 15 ternary-phase regions. No binary compound is found in the Nd-Zr binary system. No ternary compound is found in the present work. None of the phases in this system reveals a remarkable solid solution at 773 K.     

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 Al₃₀Dy₇Zr₃ has been confirmed to be existed. The maximum solid solubility of Zr in AlDy₂, Al₂Dy₃, AlDy, Al₂Dy and Al₃Dy at 773 K is determined to be 11.5 at.%, 7.8 at.%, 2.4 at.%, 22.5 at.% and 2.5 at.%, respectively.     

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. CoZr₃, CoZr₂, CoZr, Co₂Zr, Co₂₃Zr₆, Co₁₁Zr₂, TiCo₃, h-TiCo₂, c-TiCo₂, TiCo, Ti₂Co in the system. The existence of two ternary compounds Co₁₀Ti₇Zr₃ and Co₆₆Ti₁₇Zr₁₇ has been confirmed at 773 K. Co₂Zr, CoZr₃ and TiCo have a range of homogeneity. The solubilities of Ti in CoZr was determined to be up to 8.1 at.% Ti.     

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. Pr₅Si₃, Pr₅Si₄, PrSi, PrSi₂, ZrSi₂, ZrSi, Zr₅Si₄, Zr₃Si₂ and Zr₂Si 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.     

Isothermal section of Dy-Zr-Si ternary system at 773 K

The isothermal section of the phase diagram of the Dy-Zr-Si ternary system at 773 K was determined by X-ray diffraction (XRD) analysis, metallographic analysis, and scanning electron microscopy (SEM) with energy-dispersive spectrometer (EDS) analysis. The isothermal section consists of 13 single-phase regions, 23 two-phase regions, and 11 three-phase regions. The solubilities of Zr in Dy, Dy5Si4, Dy5Si3, DySi, DySi2, DySi1.67, and Dy in Zr, Zr2Si, Zr3Si2, Zr5Si4, ZrSi, and ZrSi2 were determined at 773 K.     

Phase evolution and dendrite growth in laser cladding of aluminium on zirconium

Aluminium was laser clad on a pure zirconium substrate using the blown powder method. The microstructure across the laser-clad coating was studied. Starting from the bottom to the top surface of the coating, a series of phase evolutions had occurred: (Zr) → (Zr) + AlZr₂ + AlZr₃ → Al₄Zr₅ + Al₃Zr₂ → Al₃Zr₂ + AlZr₂ → Al₂Zr → Al₂Zr + Al₃Zr. This resulted in an epitaxial columnar crystal growth at the re-melt substrate boundary, a band of backward growth Al₃Zr₂ dendrites towards the lower half of the coating, and a two-phase eutectic dendritic growth of Al₂Zr + Al₃Zr towards the top of the coating. The evolution of the various phases and microstructures is discussed in conjunction with the Al-Zr phase diagram, the criteria for planar interface instability, and the theory of eutectic growth under rapid solidification conditions (the TMK model).     

Experimental Investigation of Phase Equilibria in Ti–Zr–Ge System

Phase equilibria in the Ti–Zr–Ge ternary system at 1073 and 1173 K were investigated experimentally using equilibrated alloys with electron probe microanalysis and x-ray diffraction analysis. No ternary compounds were detected. Eleven and nine three-phase regions were determined in the Ti–Zr–Ge isothermal section at 1073 and 1173 K, respectively. Intermediate compounds ZrGe₂, Zr₅Ge₄, Zr₅Ge₃, Ti₅Ge₄, and Ti₅Ge₃, possessing large solubility, extended along the Ge isoconcentration line, indicating remarkable substitution of Ti for Zr in the Zr–Ge compounds or of Zr for Ti in the Ti–Ge compounds. The solubility of Ti in ZrGe₂ increased from 16.0 at.% at 1073 K to 19.3 at.% at 1173 K, while that of Zr in Ti₅Ge₃ remained nearly 41.0 at.% at both 1073 and 1173 K.     

Experimental determination of 800 °C isothermal section in Al-Zn-Zr ternary system

The 800 °C isothermal section in the Al-Zn-Zr system was investigated using the equilibrated alloy method and the solid/liquid diffusion couple approach by means of scanning electron microscopy equipped with energy dispersive spectroscopy, X-ray powder diffraction and electron probe microanalysis. Thirteen three-phase regions are experimentally confirmed in the ternary system. A ternary compound Zn₅₀Al₂₅Zr₂₅ named as T phase exists stably in the 800 °C isothermal section. Its composition range varies widely (16.84-55.1 at.% Zn, 18.02-56.3 at.% Al and 26.0-28.53 at.% Zr), and it can be in equilibrium with all the binary compounds. The maximum solubilities of Zn in Zr₃Al, Zr₂Al, Zr₃Al₂, Zr₄Al₃, ZrAl, Zr₂Al₃, ZrAl₂ and ZrAl₃ are 7.5, 0.84, 0.33, 0.89, 0.91, 1.12, 0.64 and 3.8 at.%, respectively. The maximum solubilities of Al in Zn₃Zr, Zn₂Zr and ZnZr are 1.6, 1.3 and 13.6 at.%, respectively.     

Isothermal section of the Co-Er-Y ternary system at 500 °C

The isothermal section of the phase diagram of the Co-Er-Y ternary system at 500 °C was investigated by X-ray powder diffraction technique, differential thermal analysis, scanning electron microscopy with energy dispersive analysis and optical microscopy. The 500 °C isothermal section consists of 14 single-phase regions, 19 two-phase regions, and 6 three-phase regions. Six pairs of corresponding compounds Er₂Co₁₇ and Y₂Co₁₇, Er₂Co₇ and Y₂Co₇, ErCo₃ and YCo₃, ErCo₂ and YCo₂, Er₄Co₃ and Y₄Co₃, Er₃Co and Y₃Co and metals Y and Er form a continuous series of solid solutions. The maximum solid solubility of Y in the compounds Er₁₂Co₇ is about 19 at.% Y.     

Isothermal section of the Gd–Co–V ternary system at 773 K

The isothermal section of the phase diagram of the Gd–Co–V ternary system at 773 K was investigated by X-ray powder diffraction (XRD), metallographic analysis, electron probe microanalysis, and differential thermal analysis (DTA) techniques. The isothermal section consists of 14 single-phase regions, 26 two-phase regions and 13 three-phase regions. The solid solubilities of V in the compounds Co₁₇Gd₂, Co₃Gd, Co₂Gd, Co₇Gd₁₂ and CoGd₃ were about 10.0, 2.0, 6.0, 1.2 and 5.3 at.% V, respectively. It was found that there are some homogeneity range in the only ternary compound of GdCo_12−xV_x with x = 2.6–3.7 at 773 K. No solubility of Gd in compounds Co₃V, σCoV or CoV₃ was observed. There is no solubility of V in Co₇Gd₂ or Co₃Gd₄ observed at 773 K.     

Phase Equilibria of the Al-Mo-Dy Ternary System at 873 K

The phase relationship in the Al-Mo-Dy ternary system at 873 K has been investigated mainly by means of x-ray powder diffraction and scanning electron microscopy. The existences of ten binary compounds (i.e. AlMo₃, Al₈Mo₃, Al₄Mo, Al₅Mo, Al₁₂Mo, AlDy₂, Al₂Dy₃, AlDy, Al₂Dy and Al₃Dy) and one ternary compound (Al₄₃Mo₄Dy₆) have been confirmed. A new ternary compound Al₄Mo₂Dy (with a similar structure of the reported Al₄Mo₂Er) was found in the system. The 873 K phase diagram of this system consists of 15 single-phase regions, 29 two-phase regions and 15 three-phase regions. The maximum solid solubility of Al in AlMo₃ and Al₈Mo₃ is about 6 and 5 at.%, respectively.     

Phase Diagrams of the Ce-Si-Zr Ternary System at 773 and 1173 K

The phase equilibria of the Ce-Si-Zr ternary system at both 773 and 1173 K have been investigated by means of powder x-ray diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analysis (DTA). The existence of 11 binary compounds, Ce₅Si₃, Ce₃Si₂, Ce₅Si₄, CeSi, Ce₃Si₅, CeSi₂, Zr₂Si, Zr₃Si₂, Zr₅Si₄, ZrSi and ZrSi₂ was confirmed. No ternary compounds were observed. Both isothermal sections consist of 14 single-phase regions, 25 two-phase regions, and 12 three-phase regions.     

The isothermal section of the Gd–Ni–V ternary system at 773 K

The phase equilibria of the Gd–Ni–V system at 773 K were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). The experimental results show no existence of ternary compounds at 773 K. The existence of 14 single-phase regions, 25 two-phase regions and 12 three-phase regions was determined. The maximum solubility of V in (Ni), Gd₂Ni₁₇, GdNi₅ and GdNi₂ was measured to be about 16 at.%, 2 at.%, 3 at.% and 2.5 at.%, respectively, while that of Gd in (Ni), Ni₃V, Ni₂V, Ni₂V₃, NiV₃ and (V) was less than 1 at.%. An isothermal section of the Gd–Ni–V system at 773 K has been presented according to the present work.     

Phase Equilibria of the Er-Si-V Ternary System at 1173?K

The phase equilibria of the Er-Si-V ternary system at 1173?K has been investigated mainly by means of powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analysis (DTA). 8 binary compounds, namely Er₅Si₃, Er₅Si₄, ErSi, Er₃Si₅, Si₂V, Si₅V₆, Si₃V₅ and SiV₃ have been confirmed. No binary compound was found in the Er-V binary system, and no ternary compound has been found in this isothermal section. The maximum solid solubility of Si in V is about 4?at.%. Er₃Si₅ has a narrow homogeneity range (from 61 to 62.5?at.% Si) while the homogeneity range of SiV₃ is from 22 to 25?at.% Si. No remarkable solid solubility of the elements in any of the other phases has been observed. The isothermal section consists of 11 single-phase regions, 19 two-phase regions, and 9 three-phase regions.     

Isothermal section of the Ho-Co-Fe system at 773 K

The 773 K isothermal section of the phase diagram of the Ho-Co-Fe ternary system was investigated by using X-ray diffraction technique, metallographic analysis and scanning electron microscopy with energy dispersive analysis. The isothermal section of the ternary system consists of 6 three-phase regions, 16 two-phase regions and 11 single-phase regions. Three pairs of corresponding compounds of Ho-Co and Ho-Fe systems, i.e., Ho₂Co₁₇ and Ho₂Fe₁₇, HoCo₃ and HoFe₃, HoCo₂ and HoFe₂, form a continuous series of solid solution. At 773 K the compound Ho₆Fe_23−xCo_x was found to have a wide homogeneity range from 0 to 29 at.% Co. The maximum solid solubilities of Fe in Co, Ho₂Co₇, Ho₁₂Co₇ and Ho₃Co were determined to be about 10, 9, 2 and 5 at.% Fe, respectively. The maximum solid solubility of Co in Fe is found to be 78 at.% Co.     

Phase equilibrium in the Cu–Ni–Zr system at 800 °C

The isothermal cross-section through the ternary Cu–Ni–Zr phase diagram at 800 °C was constructed by means of diffusion couples and equilibrated alloys. Two ternary phases Cu_20–40Ni_40–60Zr₂₀ and Cu_20–25Ni_60–65Zr₁₅ exist in the system at this temperature. Most of the Cu–Zr and Ni–Zr binary intermetallic phases show large solubility range extending to the ternary region and the solubility ranges are determined. Although Cu₁₀Zr₇ and Ni₁₀Zr₇ binary phase have the same crystal structure oC68, both phases did not form complete solid solution phase. Electron Microprobe analysis was used to determine the phase composition.     

The Al-Er-Mg ternary system Part I: Experimental investigation

Investigation of phase equilibria in the ternary system Al-Er-Mg has been carried out by means of differential thermal analysis (DTA), powder x-ray diffraction (XRD), light optical microscopy (LOM), scanning electron microscopy (SEM), and quantitative electron probe microanalysis (EPMA). The isothermal section at 400 °C has been established. An extended homogeneity region with Al substitution for Mg at a constant Er content has been found for (Mg_1−x Al _x )Er (0≤x≤0.78); a few other boundary binary phases give lower ternary solubility. A ternary compound, τ, of Al_66.7Er₁₀Mg_23.3 stoichiometry, has been found to exist in the isothermal section at 400 °C.     

The Al-Er-Mg ternary system Part I: Experimental investigation

Investigation of phase equilibria in the ternary system Al-Er-Mg has been carried out by means of differential thermal analysis (DTA), powder x-ray diffraction (XRD), light optical microscopy (LOM), scanning electron microscopy (SEM), and quantitative electron probe microanalysis (EPMA). The isothermal section at 400 °C has been established. An extended homogeneity region with Al substitution for Mg at a constant Er content has been found for (Mg_1−x Al _x )Er (0≤x≤0.78); a few other boundary binary phases give lower ternary solubility. A ternary compound, τ, of Al_66.7Er₁₀Mg_23.3 stoichiometry, has been found to exist in the isothermal section at 400 °C.     

Phase Equilibria of the Al-Sc-Zr Ternary System at 500 °C

Phase equilibria of the Al-Sc-Zr ternary system at 500 °C have been experimentally investigated by determining twenty-seven equilibrium alloys. X-ray diffraction and electron probe microanalysis were used to identify the phases and their compositions. The isothermal section of the Al-Sc-Zr system at 500 °C was constructed based on the experimental results and the information on the three constituent binary systems. Sixteen two-phase equilibrium regions and ten three-phase equilibrium regions were included and no ternary compounds were observed. The experimental results indicated that all the binary intermetallic compounds exhibited appreciable solubility of the third component. Besides, the continuous solid solution θ (Al(Sc, Zr)₂) forms between AlSc₂ and AlZr₂.     

Phase Equilibria of the Al-Co-Zn System at 450 °C

The 450 °C isothermal section of the Al-Co-Zn ternary system was determined experimentally by means of scanning electronic microscopy coupled with wave dispersive x-ray spectroscopy, and x-ray powder diffraction. Nine three-phase regions have been confirmed experimentally. The liquid phase is in equilibrium with all Al-Co compounds except Al₃Co. The maximum solubility of Zn in AlCo, Al₅Co₂, Al₉Co₂ and Al₁₃Co₄ is 8.76, 18.14, 1.24, 8.97 at.%, respectively. The Al solubility in the Co-Zn compounds (γ₂, γ₁, γ, β₁) is very small, no more than 0.14, 0.28, 0.32, and 0.62 at.%, respectively. No true ternary compound was found in the present study.