Fe Ternary Alloy Research Articles

Theoretical Investigation of Thermodynamic Properties of the Al-Si-Fe Ternary Alloy.

Aiming at the current lack of thermodynamic parameters related to the preparation of aluminum-silicon-iron alloys from spent refractory materials in aluminum electrolytic cells, the Miedema model was used to calculate the thermodynamic parameters of Al-Si, Al-Fe, and Si-Fe binary alloys. On this basis, the Toop model was combined to calculate the mixing enthalpy ΔH, excess entropy SE, excess Gibbs free energy GE, and component activity α of Al-Si-Fe ternary alloys. The results show that ΔH, SE, and GE of binary alloys are all negative values. The properties of the Al element and Si element are similar, and they are different from the Fe element. The ternary alloys also have negative values of ΔH, SE, and GE in the alloy composition range, and their values change obviously in the region where the content of Fe is high or low. The activity values of all components decrease dramatically along with the diminishing of the corresponding molar fractions, and the activity values of Al, Si, and Fe are smaller in the central portion of the triangle of ternary components. It indicates that there is a strong interaction between the three elements, which easily forms ternary intermetallic compounds.

Study on Electrical, Thermal, Magnetic Properties and Microstructure for - Al, -Al2Cu, ω-Al7Cu2Fe Phases in Al-32.5 wt. % Cu-1 wt. % Fe Ternary Alloy

The electrical properties of the Al-32.5 wt. % Cu-1 wt. % Fe ternary alloy were examined, it was observed that the electrical resistivity increased depending on the temperature and it was found as 6.8546x10-8 Ωm - 5.7780x10-7Ωm in the temperature range of 298-810K. The thermal conductivity was calculated using electrical measurement results and it was observed that it decreased depending on the temperature. The ternary alloy (cubic -Al, Fm-3m, 225 a = 4.0480 Å, -tetragonal Al2Cu, I4mcm, 140, a=6.0654 Å c=4.8732 Å, ω-tetragonal Al7Cu2Fe, P4 /mnc, 128, a = 6.3360 Å, m and c = 14.87 Å) phases were obtained. In this ternary alloy, phases were clearly seen in XRD studies and EDAX analyzes at room temperature. Magnetic properties such as magnetic transition temperature and magnetization curves of the alloy were determined.

Atomic-level prediction of V–Ni–Al, V–Ni–Co and V–Ni–Fe ternary alloys as highly selective hydrogen separation membranes

VB-group-based ternary alloys membranes for hydrogen separation have attracted great attention because of their superiorities on selectivity and permeability of hydrogen. However, atomic-scale hydrogen separation properties of the ternary alloys are still not studied, further related study is critical for developing high-performance V–Ni-based alloys membranes. In this work, molecular dynamics (MD) and first-principles calculation are incorporated to predict performances of V–Ni–Al, V–Ni–Fe and V–Ni–Co ternary alloys for separation of H2 from N2, CO2, CO, CH4, H2O and H2S mixed gases. Based on calculations of adsorption properties, diffusion energy barrier, selectivity and charge density difference, it reveals that the alloys membranes show excellent permeance and selectivity for separation of hydrogen gas. In particular, V–Ni–Al membrane presents superior diffusion and permeability properties for hydrogen gas. Our calculations provide an insight into atomic-level mechanism of V–Ni–Al, V–Ni–Fe and V–Ni–Co alloys as high-performance hydrogen separation membranes.

Diffusion coefficient measurement and atomic mobility assessment for bcc Ti–V–Fe ternary alloys

Diffusion behaviors in bcc Ti–V–Fe ternary alloys have been investigated at 1273 K and 1473 K by the diffusion couple technique. The composition-distance profiles have been retrieved from Electron Probe MicroAnalysis (EPMA) and analytically represented by the ERror Function EXpansion (ERFEX), and then the ternary inter-diffusion and impurity diffusion coefficients have been extracted by Whittle–Green and generalized Hall methods, respectively. The extracted inter-diffusion coefficients of D˜VVTi and D˜FeFeTi range from 0.89 × 10−13 m2/s to 1.86 × 10−13 m2/s and from 1.33 × 10−12 m2/s to 1.76 × 10−12 m2/s, respectively, at 1273K, and from 6.41 × 10−13 m2/s to 15.98 × 10−13 m2/s and from 82.46 × 10−13 m2/s to 147.08 × 10−13 m2/s at 1473K. D˜VVTi exhibits the similar compositional variation at both temperatures, which decrease with decreasing Fe and minimize at the Ti–V binary. D˜FeFeTi has the maximum value at Ti–corner and eventually decreases with the increasing V and Fe at 1273K, but has the maximum value at Fe-rich Ti–Fe binary and decreases with the increasing V. The atomic mobility parameters of Ti–V, Ti–Fe and V–Fe binary systems have been revised to associate with the lasted ternary interaction parameters in thermodynamics. The ternary atomic mobility parameters for diffusion have been assessed for the first time by reproducing the extracted diffusion coefficients. The composition-distance profiles and the diffusion paths have been successfully reproduced by using the optimized atomic mobility parameters showing a consistency with the experimental data and indicating the accuracy of this work.

Phase diagram of the Al–Cu–Fe quasicrystal-forming alloy system

Abstract The microstructures of as-cast and slowly solidified Al– Cu–Fe ternary alloys in the vicinity of the icosahedral phase region have been investigated using light microscopy and scanning electron microscopy. The chemical composition of the different phases present has been determined by energy-dispersive X-ray spectroscopy with a correction of electron probe microscopy analysis. The solidification process was studied by means of the differential thermal analysis and magnetothermal analysis measurements. In contrast to the equilibrium phase diagram, fast cooling leads to the formation of a metastable β′ phase (an ordered cubic structure) rather than to the formation of the φ phase. The nucleation of ω phase is very sluggish during the solidification. The results are presented as solidification paths, superimposed onto the liquidus surface projection to demonstrate the solidification sequences.

Corrosion resistance of ultrasonic electrodeposited Ni-Co-Fe ternary alloy films according to current density.

Ni-Co-Fe ternary alloy films were deposited on Copper clad laminate (CCL) by ultrasonic electroplating at different current densities from a sulfate bath. The corrosion properties of the ultrasonically-electrodeposited Ni-Co-Fe films were investigated by electrochemical impedance spectroscopy (EIS). We found that Ni, Co, and Fe component ratios changed according to the current density. The Ni content increased when the current density increased, but the Co and Fe content of the films decreased. Ni-Co-Fe ternary alloy films with a high Ni content and lower Fe content showed good resistance to corrosion. We also found that ultrasonically-electrodeposited Ni-Co-Fe films had higher corrosion resistance than non-ultrasonically electrodeposited Ni-Co-Fe films. Ultrasonically electrodeposited Ni-Co-Fe films had a higher Ni content than electrodeposited Ni-Co-Fe ternary alloys. X-ray diffraction analysis revealed that the Ni-Co-Fe films comprised a mixture of both FCC (face centered cubic) and BCC (body centered cubic) structures.

Modelling of Al-7%wtSi-1wt%Fe Ternary Alloy: Application to Space Experiments with a Rotating Magnetic Field

Recently several experiments on directional solidification of Al-6.5wt.Si-0.93wt.%Fe (AlSi7Fe1) alloy were performed under terrestrial conditions and onboard the International Space Station (ISS) in the Materials Science Lab (MSL) with use of electromagnetic stirring and without it. Analysis of the samples showed that stirring with a rotating magnetic field lead to the accumulation of iron-rich intermetallics in the center of the sample and influenced the primary dendrite spacing while the secondary dendrite arm spacing were not affected. In the present paper the accumulation of the intermetallics b-Al5SiFe in the center of the samples due to RMF stirring is demonstrated numerically and the evolution of primary and secondary dendrite arm spacing is discussed.

Galvanostatic charge–discharge tests, 57Fe and 119Sn Mössbauer and XRD measurements on novel Sn-Ni-Fe electrodeposits

Novel Sn–Ni–Fe ternary alloys were successfully deposited by pulse plating technique from an electrolyte based on sodium gluconate which acts as a complexing agent. XRD results revealed the predominantly amorphous character for the majority of the deposits. 57Fe and 119Sn conversion electron Mossbauer spectroscopy indicated the formation of a paramagnetic amorphous alloy using a short on-pulse duration and where the Fe content was less than 22 wt.%. Galvanostatic charge–discharge tests of the novel Sn-Ni-Fe deposits were carried out in a model Li-ion cell and indicated that the Sn-Ni-Fe alloys have potential as an electrode material.

Study of electrodeposition of amorphous Sn–Ni–Fe ternary alloys from a gluconate based electrolyte

Novel Sn–Ni–Fe ternary phases, which never occur in the metallurgical alloys, were successfully prepared by deposition from an electrolyte based on sodium gluconate, using DC electrodeposition conditions. 57Fe and 119Sn conversion electron Mössbauer spectroscopy and PXRD investigations of these alloys showed that they are amorphous and dominantly ferromagnetic. The occurrence of amorphous Sn–Fe–Ni ternary alloy phase in deposits was found to increase with the current density applied during the deposition. The co-deposition kinetics is mainly governed by the electrodeposition behavior of the tin–gluconate complex that forms in the electrolyte. The high cathodic polarization due to the tin–gluconate discharge causes an apparent mass transfer coupled co-deposition of iron. The nickel deposition rate is independent of the potential and of the partial current of the co-depositing species.

Electrodeposition of novel Sn–Ni–Fe ternary alloys with amorphous structure

Tin–nickel–iron (Sn–Ni–Fe) ternary alloys have been successfully prepared for the first time by electrochemical deposition. 57Fe and 119Sn conversion electron Mössbauer and PXRD investigations of these alloys showed that the alloys were dominated by new metastable phases which do no occur in the thermally prepared alloys and are not to be found in the corresponding equilibrium phase diagram. Essentially these ternary alloys proved to be amorphous and ferromagnetic.

Density and related thermophysical properties of metastable liquid Ni–Cu–Fe ternary alloys

The densities of liquid Ni–Cu–Fe ternary alloy system were investigated by molecular dynamics method in combination with a MEAM ( Modified Embedded Atom Method) potential model. The temperature range is from 1000 to 2200 K, including both a broad superheating range and a large undercooled regime. The densities of six Ni 100 − 2 x Cu x Fe x alloys ( x = 0 , 10 , 20 , 30 , 40 , 50 ) decrease linearly with the rise of temperature at the superheated and undercooled states, and increase with the enhancement of Ni content. Among the simulated alloys, the densities of only liquid pure Ni and Ni 60Cu 20Fe 20 alloy are available in literatures, which are in good agreement with the calculated values. According to the relationship between the excessive volume and the alloy composition, it can be deduced that Ni 100 − 2 x Cu x Fe x alloys deviate from ideal solution. Moreover, a comparison was also performed between the calculated results and the approximated values by Neumann–Kopp's rule. Based on the obtained density data, the thermal expansion coefficients are also derived. It firstly decreases to a minimum value, and then displays a rise with the increase of Ni content.

Electrodeposition behavior of zinc–nickel–iron alloys from sulfate bath

The present work is directed at collecting the properties of Zn–Ni and Zn–Fe alloys in one alloy via the electrodeposition of Zn–Ni–Fe ternary alloy. Electrodeposition of ternary Zn–Ni–Fe alloy was investigated and compared with the characteristics of Zn–Ni electrodeposits. The electrodeposition was performed from a sulfate bath onto a steel substrate. Structural analysis by X-ray diffraction (XRD) method revealed that the Zn–Ni–Fe alloys consisted of a mixture of zinc, and (γ-Ni2Zn11) and (Fe3Ni2) phases. The study was carried out using electrochemical methods such as cyclic voltammetry and galvanostatic for electrodeposition, while anodic linear polarization resistance and anodic linear sweeping voltammetry techniques were used for the corrosion study. Surface morphology and chemical composition of the deposits were also examined by using scanning electron microscopy and atomic absorption spectroscopy, respectively. It was found that the obtained Zn–Ni–Fe alloy exhibited more preferred surface appearance and better corrosion resistance without adding any organic brighteners to the plating bath in comparison to Zn–Ni alloy that electrodeposited at similar conditions. Results obtained revealed that the increase in corrosion resistance of ternary deposits is not only attributed to the formation of (γ-Ni2Zn11) phase, but also to iron codeposition and formation of (Fe3Ni2) phase.

Coarsening of Co-rich precipitates in a Cu–Co–Fe ternary alloy

The effect of coherency on coarsening of fcc Co–Fe precipitates in a Cu–1.47 wt.%Co–0.56 wt.%Fe (Co : Fe = 7:3 in atomic ratio) alloy aged at 873–973 K has been studied by measuring both the precipitate size by transmission electron microscopy and the solute concentration in the Cu matrix by electrical resistivity measurements. The precipitate phase consists of 7 parts of Co and 3 parts of Fe in atomic ratio, irrespective of the precipitate size. The precipitates smaller than about 8 nm in radius are coherent with the Cu-matrix. When the average precipitate radius is over 18 nm, all the precipitates become semi-coherent. The coarsening rates are not affected by the coherency of the precipitates. The precipitate/matrix interface energy γ has been derived, independently of the diffusivities of solute atoms using a coarsening model developed by Kuehmann and Voorhees for ternary systems. The precipitates are coherent or semi-coherent with the matrix, the experimentally obtained value of γ is 0.2 J/m2. This value lies between the reported values of γ = 0.15 J/m2 for Co precipitates and γ = 0.25 J/m2 for γ-Fe precipitates.

Microstructural investigation of phase transformations and properties during thermal processing of a 6 w/oAl-modified Ni–Cr–Fe ternary alloy

A differential scanning calorimetric study was carried out on a P/M processed Inconel 600 (Ni–Cr–Fe)-based superalloy modified by the addition of 6 w/o Al to study sequence of phase transformations, their reaction modes and products on heating a green compact from room temperature to the sintering temperature of 1300 °C. Two different heating rates were employed for the DSC study, 2.5 °C/min and 10 °C/min. Transformation reactions were also studied by heating the samples in a DSC to the points of exo/endothermicity and quenching in argon followed by phase identification by X-ray diffraction, and microstructural analysis by SEM equipped with EDS capability. A series of Al x Ni y - and Al x Fe y -type intermetallics were observed to form by phase transformation at temperatures from 540 °C to 1120 °C. The sequence of the formation of intermetallics by those phase transformation closely replicated the intermetallics that were predicted by the binary Ni–Al and the Fe–Al equilibrium phase diagrams to form, with the final microstructure being Ni 3Al ( γ′), AlNi, AlFe in a Ni–Cr–Fe ( γ) matrix. Most of these phase transformations were diffusion-controlled, however at 640 °C AlNi formed by combustion synthesis. Selected mechanical property of the alloy at 1120 °C which corresponds to the completion of transformation was estimated in terms of micro-hardness and compared to the as-sintered ternary.

Microstructural response of an Al-modified Ni–Cr–Fe ternary alloy during thermal processing

A thermodynamic package was used to predict the phase transformations that occurred during thermal processing of a superalloy based on the composition of a ternary Ni–Cr–Fe alloy. The effect of the addition of 6 w/o Al on phase transformation in the material sintered were estimated and compared with results obtained experimentally by X-ray diffraction and metallography, while the transformation temperature of the modified alloy was corroborated by differential scanning calorimetry (DSC). Mechanical property of the alloy was estimated in terms of Vickers hardness. These results suggest that despite potential problems encountered in high-temperature powder processing of superalloys that often tend to influence the feasibility of using thermodynamic predictions to model such alloy systems, the software and predictions used in this study offer a way to simulate both design and characterisation of the experimental alloy.

Preparation and characterisation of electrodeposited amorphous Sn–Co–Fe ternary alloys

Electrochemical deposition was investigated as a process to obtain alloys of Sn–Co–Fe, which to date have not been reported in the literature. A constant current technique was used to electrochemically deposit tin–cobalt–iron alloys from a gluconate electrolyte. The gluconate system was chosen as an electrolyte, which could potentially provide an environmentally safe process. The effect of plating parameters such as current density, deposition time, temperature and pH are discussed. Results are reported for current density and plating time using an electrolyte temperature of 20–60 °C and pH of 7.0 in relation to phase composition, crystal structure and magnetic anisotropy of the deposited alloys. Investigations were conducted using 57Fe conversion electron Mössbauer spectroscopy (CEMS), 119Sn CEMS, transmission Mössbauer Spectroscopy and XRD. The 57Fe and 119Sn CEMS spectra and XRD showed that the dominant phase in the deposits was amorphous Sn–Co–Fe. The relative area of the 2nd and 5th lines of the sextets representing the magnetic iron containing phases was found to decrease continuously with increasing current density while at the same time no significant changes in the magnetic anisotropy was found with plating time. Magnetically split 119Sn spectra reflecting a transferred hyperfine field were also observed. A range of good quality amorphous Sn–Co–Fe ternary alloys was obtained over a range of operating conditions from an environmentally acceptable gluconate electrolyte.

Fabrication of fiber-reinforced functionally graded materials by a centrifugal in situ method from Al–Cu–Fe ternary alloy

Abstract Ternary Al–13.8at%Cu–1.6at%Fe alloy was prepared from Al–Cu and Al–Fe alloys at 1000 °C. The ternary Al–Cu–Fe alloy was centrifugally cast to fabricate a new type of functionally graded material (FGM) by a centrifugal in situ method. The structure is expected to differ from that of binary alloys. It was found that the fabricated FGM rings consist of four different phases, namely, Al, Al2Cu, Al7Cu2Fe(ω) and Al13Fe4 phases. The shape of ω phase was fiber (needle) judging from the observation by a scanning acoustic microscope (SAM). The position dependence of the microstructure was examined on the fabricated FGM rings, and the volume fraction of ω phase was found to increase toward the outer region of the ring. Moreover, orientation and aspect ratio of the ω phase varied in the rings in a gradually graded manner. Therefore, the present study explores a method to produce fiber-dispersed FGMs by applying a centrifugal in situ method to ternary alloys.

Microstructure, Fabrication and Properties of Quasicrystalline Al—Cu—Fe Alloys: A Review

For Abstract see ChemInform Abstract in Full Text.

Phase diagram of the Al–Cu–Fe quasicrystal-forming alloy system

Abstract The microstructures of as-cast and slowly solidified Al–Cu–Fe ternary alloys in the vicinity of the icosahedral phase region have been investigated using light microscopy and scanning electron microscopy. The chemical composition of the different phases present has been determined by energy-dispersive X-ray spectroscopy with a correction of electron probe microscopy analysis. The solidification process was studied by means of the differential thermal analysis and magnetothermal analysis measurements. In contrast to the equilibrium phase diagram, fast cooling leads to the formation of a metastable β′ phase (an ordered cubic structure) rather than to the formation of the φ phase. The nucleation of ω phase is very sluggish during the solidification. The results are presented as solidification paths, superimposed onto the liquidus surface projection to demonstrate the solidification sequences.

Use of Synchrotron Diffraction Data for Describing Crystal Structure and Crystallographic Phase Analysis of R‐Phase NiTi Shape Memory Alloy

Sitepu et al. (Sitepu, H., Schmahl, W.W., Khalil Allafi, J., Eggeler, G., Dlouhy, A., Reinecke, T., Brokmeier, H.G., Tovar M. and Többens, D.M. (2002b). Texture and quantitative phase analysis of aged Ni‐rich NiTi using X‐ray and neutron diffractions. Materials Science Forum, 394‐395, 237‐240.) showed that Rietveld refinement with generalized spherical harmonic (GSH) description for neutron powder diffraction (ND) data of the aged (673 K, 20 h) Ni‐rich NiTi shape memory alloy (Sitepu H. (2002). Assessment of preferred orientation with neutron powder diffraction data. J. Appl. Cryst, 35, 274–277); of nominal composition 50.7 at.% Ni at 294K consists of four phases: precipitate (Ni4Ti3), R‐phase, monoclinic (B19′) and some residual cubic (B2). Therefore, they concluded that the differential scanning calorimetry (DSC) first peak, on cooling, (321 K) is not due to the formation of the R‐phase alone. The second, lower DSC peak (271 K) is due to the transformation of R‐phase and residual B2 phase to B19′ phase. The structural refinement of R‐phase problem, which was neglected in the previous study, was undertaken with great care in this study. The objective of the present article is to use the third generation synchrotron X‐ray source at the European Synchrotron Research Facility (ESRF) in Grenoble, which make available X‐ray beams of higher energy and much higher intensity than laboratory X‐ray sources, for describing crystal structure of the R‐phase in 50.75 at.% Ti–47.75 at.% Ni–1.50 at.% Fe ternary alloy. The synchrotron diffraction data of R‐phase were analyzed using the Rietveld refinement with GSH description. The results showed that no significant improvement in fit is found when the inversion center is removed from the model, suggesting that the space group is indeed and not P3.