Binary Alloy Phase Diagrams Research Articles

Phosphorus Particle Composite Plating with Ni–P Alloy Matrix

Ni–P alloy films containing phosphorus particles (called “Ni–P alloy composite films”) were fabricated by electrodeposition and were subsequently subjected to heat-treatment. Their compositions and microstructures were characterized, and their friction properties were evaluated using a ball-on-plate method. Composite electroplating in the nickel sulfate and chloride bath containing phosphorus acid and micrometer-sized phosphorus particles resulted in the Ni–P alloy coating with enhanced deposit phosphorus content. The phosphorus content of the films increased with increasing phosphorus particle concentration in the composite plating baths, reaching a maximum value of 29.0 atom %. The phosphorus particles were homogeneously distributed in this Ni–29.0 atom % P alloy composite film. Heat-treatment converted the phases of the alloy composite films from an amorphous phase to stable crystalline phases, which are the same as those in the Ni–P binary alloy phase diagram. The friction coefficients of the Ni–P alloy films increased with increasing cycle number, whereas those of the Ni–P alloy composite films remained relatively constant. The alloy composite films had lower friction coefficients than the Ni–P alloy films both before and after heat-treatment. These results indicate that phosphorus particles are beneficial for maintaining a lower and stable friction coefficient during the ball-on-plate reciprocating friction test.

Assessing Aptitude of Plated Ni–W Film as Mold Materials for Borosilicate Glass

We propose the Ni–W plating film as a mold material for the hot embossing of borosilicate glass. The lifetime of a Ni–W plating mold is important from a practical perspective. However, there have been no previous reports on the life of a mold. Contact angle has been reported as a parameter for the comparative assessment of wettability. In this report, we identified the components of borosilicate glass reacted with a Ni–W film by elemental analysis together with a wettability test. In the wettability test, increasing temperature caused a decrease in of contact angle, which is caused by the chemical reaction at the center of glass. In the results of the elemental analysis of the Ni–W film in contact with glass, Zn, a constituent of the glass, was not detected in the noncontact zone, but was detected in the contact zone. There is no binary alloy phase diagram of W–Zn. It is considered that W does not form an alloy with Zn. Results from the reaction of Zn on Ni indicated an increase in the wettability of borosilicate glass for the Ni–W plating film.

Phase diagrams of binary alloys calculated from a density functional theory

Phase behaviors of binary alloys with an embedded atom model potential are investigated using the thermodynamic perturbation theory. The free energies of the liquid and solid phases are computed using the fundamental measure density functional theory and accurate approximations to the hard-sphere mixture correlation functions. The method is applied to calculate the Au-Cu alloy phase diagram. To improve the accuracy of the computed phase diagram, we developed a systematic approach to optimize the model potential of Au-Cu by adjusting the melting temperature of the pure Au to its experimental one. With such an optimized potential the computed Au-Cu alloy phase diagram is in good agreement with the experimental one for the whole composition range.

Thin layer in situ XRD of electrodeposited Ag/Sn and Ag/In for low-temperature isothermal diffusion soldering

In situ X-ray diffraction of thin electroplated Ag/Sn and Ag/In sandwich layers on Ni-coated copper substrates has been used to monitor the phase evolution in these systems at various temperatures. Initially, the course of the reactions in both systems, which are used in isothermal diffusion soldering, follows the transitions in their binary alloy phase diagrams. At 320 °C the composition of the reaction zone in the Ag/Sn case changes straightforward from tin-rich to silver-rich phases. In the case of Ag/In the same trend is observed, but the homogenization of the layer system is more complicated due to peritectic and metatectic reactions during heating up. The electroplated Ag/Sn and Ag/In ratios corresponded to the compositions of the respective ζ-phases. As the homogenization of the solder layers at 320 °C progressed, Ni–Sn and Ni–In phases were detected by EDX. The depletion of the Ag phases from Sn and In and formation of the solid solutions of Sn and In, respectively, in Ag were followed by in situ XRD. This technique allows studying the transformation of phases in thin layer sT:/PGN/ELSEVIER/META/web/00003803/ystems at process temperatures.

Structure of interfaces in thin-film metallic multilayer heterostructures

It is demonstrated that the structure of interfaces in thin-film metallic multilayers can be predicted from the phase diagrams of binary alloys of metals constituting the multilayers. Experimental data on the small-angle X-ray reflectivity and magnetization of the samples are used for characterizing the structure of the interfaces.

Thermodynamics and Adsorption Behaviour of the Nano Phases in the Bi-Sn System

The study of thermodynamic behaviour of the surfaces based on the derivative technique is shown to be significantly different from that of the bulk phase of the system. Nano particle binary alloy phase diagrams have been evaluated from the information on the Gibbs free energy of mixing and surface tension of the alloys using the combined form of Butler's and the Thomson-Freundlich equations. The evaluated phase diagram for the nano phases in the Bi-Sn system is found to be considerably different from the constitutional phase relations for the alloys of the planar surface. The melting temperatures of the components decrease considerably with decrease in the size of the nano particle. The reduction in melting points of the components accompanies with a decrease in the eutectic temperature of the system. The mutual solubilities of the terminal nano phases increase considerably resulting in restriction of the two phase field with consequent increase in the area of the liquid phase in the system. The deviation of the behaviour of the nano phase increases as the size of the nano particle decreases. The drop of the eutectic temperature is found to reach a minimum for 1 Nm particle. The adsorption studies of the nano phases establishes a pronounced increase in the adsorption function which increases with decrease in the size of the nano particle.

Transient microstructural evolution of infrared brazed Fe 3Al intermetallics using aluminum foil

The present work reports a novel approach in joining Fe 3Al by infrared brazing using the pure Al as brazing filler metal. Based on the Al–Fe binary alloy phase diagram, the species and morphology of phases as well as the transient evolution of microstructures in the infrared brazed joint are extensively studied. The Fe 3Al substrate is dissolved into the molten braze, and reacts simultaneously with the Al-rich melt during infrared brazing. Various iron aluminides such as FeAl 3, Fe 2Al 5, FeAl 2, FeAl and eutectoid FeAl 2–FeAl are observed in the infrared brazed joint for different brazing temperatures. For brazing temperatures between 700 and 1000 °C, the dendritic morphology of Fe 2Al 5 phase dominates the infrared brazed joint. For brazing temperatures between 1050 and 1200 °C, solid-state interdiffusion of aluminum and iron among reaction products and base metal is followed by isothermal solidification of the molten braze. Primary FeAl and eutectoid FeAl–FeAl 2 are widely observed in the infrared brazed joint. Further increasing the brazing temperature and/or time, the interface between the braze alloy and substrate is finally disappeared.

The Ti-Si-C system (Titanium-Silicon-Carbon)

In the present article different isothermals of Ti-Si-C system at temperatures ranging from 1250 to 2877 °C, previously reported by [1966Bru], [1989Tou], [1991Wak], and [1993Sei1], were assessed and redrawn on the basis of the recently reported binary alloy phase diagram of Ti-Si, Ti-C, and Si-C.

Phase diagram of binary Ti-Ni alloys on Ti-rich side under a pressure of 2.2 GPa

Phase diagram of binary Ti-Ni alloys on Ti-rich side under a pressure of 2.2 GPa

Selecting metal alloy electric contact materials for MEMS switches**The views expressed in this paper are those of the authors and do not reflect the official policy or position of the United States Air Force, Department of Defense, or the US Government.

This paper presents a method for selecting metal alloys as the electric contact materials for microelectromechanical systems (MEMS) metal contact switches. This procedure consists of reviewing macro-switch lessons learned, utilizing equilibrium binary alloy phase diagrams, obtaining thin film material properties and, based on a suitable model, predicting contact resistance performance. After determining a candidate alloy material, MEMS switches were designed, fabricated and tested to validate the alloy selection methodology. Minimum average contact resistance values of 1.17 and 1.87 Ω were measured for micro-switches with gold (Au) and gold–platinum (Au–(6.3%)Pt) alloy electric contacts, respectively. In addition, ‘hot-switched’ life cycle test results of 1.02 × 108 and 2.70 × 108 cycles were collected for micro-switches with Au and Au–(6.3%)Pt contacts, respectively. These results indicate increased wear with a small increase in contact resistance for MEMS switches with metal alloy electric contacts.

An application of the dynamical mean-field approximation to ferromagnetic alloys

The effect of the fluctuation of local correlation in the phase diagram of binary ferromagnetic alloy is investigated by using the coherent potential approximation and the dynamical mean field approximation. The Curie temperature varies smoothly as the function of the concentration. This behaviour is different from the phase diagram which is calculated by the Hartree–Fock approximation.

LOCAL GROWTH OF SOL-GEL FILMS BY MEANS OF MICROHOTPLATES

International Journal of Computational Engineering ScienceVol. 04, No. 03, pp. 563-568 (2003) Poster PapersNo AccessLOCAL GROWTH OF SOL-GEL FILMS BY MEANS OF MICROHOTPLATESF. CALAME, J. BABOROWSKI, N. LEDERMANN, and P. MURALTF. CALAMECeramics Laboratory, Engineering Faculty, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland Search for more papers by this author , J. BABOROWSKICeramics Laboratory, Engineering Faculty, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland Search for more papers by this author , N. LEDERMANNCeramics Laboratory, Engineering Faculty, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland Search for more papers by this author , and P. MURALTCeramics Laboratory, Engineering Faculty, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland Search for more papers by this author https://doi.org/10.1142/S1465876303001769Cited by:2 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail AbstractPZT(PbZrxTi1-xO3) thin films have been locally grown by means of sol-gel deposition and local anneals on microhotplate. The microhotplate was based on a tantalum silicide filament (Ta5Si3) formed on stress compensated SiN/SiO2 membrane. On this filament, a passivation layer of SiO2, a layer of Ti/TiO2 and a bottom electrode of Pt were deposited. Due to the low heat conductivity of the membrane, crystallization of the PZT film occurs exactly on the resistor filament. The formation of crystalline, i.e. perovskite PZT was verified by means of X-ray diffraction. A random PZT texture has been observed.Keywords:Hotplatestantalum silicidelocal growthPZT References A. Pollien, J. Baborowski, N. Ledermann and P. Muralt, "New material for thin film filament of micromachined hot-plate", Proceedings of the 11th conference on solid-state sensors and actuators, Transducers'2001, Munich, pp. 848-851 (2001) . Google ScholarM. Ehmannet al., Proceedings of MEMS'01 (2001) pp. 147–150. Google Scholar T.B. Massalski, "Binary alloy phase diagrams", 2nd ed Vol. 1-3, 1990, ASM International . Google ScholarM.-A. Nicolet, Mat. Res. Soc. Symp. Proc. 40, 317 (1985). Crossref, Google ScholarS. P. Muraka, J. Vac. Sci. 17(4), 775 (1980). Crossref, Google ScholarK. Brookset al., J. Mater. Res. 9(10), 2540 (1994). Crossref, Google Scholar FiguresReferencesRelatedDetailsCited By 2Design of a Flexible Stethoscope Sensor Skin Based on MEMS TechnologyHonghai Zhang, Maozhou Meng, Xiayun Shu and Sheng Liu1 Aug 2006Microfabrication of Piezoelectric MEMSJ. Baborowski1 Jan 2005 Recommended Vol. 04, No. 03 Metrics History KeywordsHotplatestantalum silicidelocal growthPZTPDF download

Texture of Cu and dilute binary Cu-alloy films: impact of annealing and solute content

The impact of 11 alloying elements, namely Mg, Ti, In, Sn, Al, Ag, Co, Nb and B, at two nominal concentration of 1 and 3 at%, and Ir and W, at only a nominal concentration of 3 at%, on the evolution of texture of Cu was investigated. The behavior of the alloy films was compared with that for a pure Cu film. The films were electron beam evaporated onto oxidized Si wafers and had thicknesses in the range of 420–560 nm. Annealing was carried out at 3°C/s to 400°C, 650°C and 950°C. For the lowest annealing temperature, the samples were held isothermally for 5 h, while for the higher annealing temperatures, the samples were cooled immediately after reaching temperature. In all cases, annealing resulted in the strengthening of film texture. For most of the films, the 〈1 1 1〉 component either remained or became the strongest fiber component with the increase in annealing temperature. The interesting exceptions were the two Mg-containing films for which the 〈1 1 0〉 component was the strongest. Whereas in the as-deposited state all alloy films, except the nominally 3 at% Nb film, had weaker textures than pure Cu, certain combinations of alloy concentration and annealing conditions resulted in more strongly textured films when compared with pure Cu. For example, the most strongly textured film after the 400°C and 950°C anneals were, respectively, Cu(Ti) and Cu(Nb), both nominally 3 at%. Film texture was also related to grain growth for the 400°C-annealed films. The behavior of the alloy films is discussed in terms of the various driving and pinning forces for grain growth and texture evolution in thin films. No simple correlations of alloy film behavior with atom size, electronegativity or the binary alloy phase diagram were found.

Comments on the Li-Sr system as shown in ASM’s Binary alloy phase Diagrams

Comments on the Li-Sr system as shown in ASM’s Binary alloy phase Diagrams

First-principles calculations for point-defect energies in metals and phase diagrams of binary alloys

We discuss the present status of the first-principles electronic-structure calculations for defect energies in metals. The calculations apply density functional theory in the generalized-gradient approximation of Perdew and Wang, together with a full-potential version of Korringa–Kohn–Rostoker Green's function method, developed by the Jülich group. It is shown that: (1) the present calculations reproduce very well the experimental results for vacancy formation energies in metals, as well as the bulk properties such as equilibrium lattice parameters and bulk moduli of metals; and (2) the type of the phase diagram of a binary A–B alloy can be characterized by the interaction energies between a pair of impurity B (A) atoms in the host metal A (B). The observed temperature dependence of the solid solubility limit of Rh in Pd is also reproduced very well by the free-energy calculations based on the cluster variation method with the pair- (up to the eighth neighbor) and many-body (up to a tetrahedron of first-nearest neighbors) interaction energies, all of which are determined by the present first-principles calculations.

Full-Potential KKR Calculations for Point Defect Energies in Metals, based on the Generalized-Gradient Approximation: II. Impurity-Impurity Interaction Energies and Phase Diagrams

We present systematic first-principles calculations for impurity-impurity interaction energies (Eint) of 4d elements in 4d bcc metals Nb and Mo, and 4d fcc metals Pd and Ag. The calculations are based on the generalized-gradient approximation in density-functional formalism, proposed by Perdew and Wang in 1991 (PW91-GGA), and apply the full-potential Korringa-Kohn-Rostoker (FPKKR) Green’s function method for point defects, developed by the Julich group. First we examine the distance dependence, from 1st to 8th neighbors, of Eint and show that for most cases, the 1st nearest-neighboring impurity-impurity interaction energies (Eint1) are dominant. Second it is shown that most of the types of phase diagrams of binary alloys of impurity and host elements, such as segregation, solid solution, and order, known experimentally, may be very well discriminated by use of the sign and magnitude of Eint1. Third we show that the temperature dependence of solid solubility limit of Rh in Pd, which is segregated at low temperatures and becomes disordered at high temperatures, are reproduced fairly well by the free-energy calculations based on the cluster variation method with the present results for Eint (up to the 8th neighbor). It is also shown that the inclusion of the impurity-cluster interaction energies up to the four-body (a tetrahedron of 1st-nearest neighbors), being also determined by the present first principles calculations, leads to the complete agreement with the experimental result. We also show that the chemical trend for Eint1 is understood by use of the Friedel’s band filling mechanism for d-states, if the dependence of the band width on element is taken into account in the model.

銅基二元系状態図の液相線および固相線におよぼす合金元素の影響

Various copper alloys applied to electric and electronic use undergo the casting process as the first step of production. But a fully systematic investigation of their castability has not yet been attempted. In this work, liquidus gradients and solidification temperature ranges were acquired from phase diagrams of binary copper alloys and were arranged on the periodic table. As a result, it became clear that the liquidus gradients of the same group on the periodic table are almost constant, and elements that enlarge the solidification temperature range exist in the continuous areas around 2A and 6B groups on the periodic table. This result shows that these characteristics above mentioned seem to stem from the nature of the added elements and it is considered that they are also practically useful for estimating the castability of new alloys.

High pressure phase diagrams of binary lanthanide alloys between La, Ce and Pr

In comparison with the “regular” binary alloy phase diagrams between “regular” trivalent lanthanide metals, binary intralanthanide alloys of Ce exhibit many irregularities typical for Ce under pressure due to its f electron delocalization. For comparison with the La-Ce and Ce-Pr high pressure phase diagrams also the more regular La-Pr data are presented for the pressure range up to 40GPa.

Phase diagram of a model alloy with lattice misfit

The influence of elastic interactions on the phase diagram of a two-dimensional model binary alloy with antiferromagnetic nearest and ferromagnetic next-nearest-neighbor-type interactions is studied by Monte Carlo simulations and finite size scaling techniques. The elastic interaction leads to a reduction of the critical and tricritical temperatures compared to model without elastic interactions.

Dissociation of dilute immiscible copper alloy thin films

The dissociation behavior of dilute, immiscible Cu-alloy thin films is found to fall into three broad categories that correlate most closely with the form of the Cu-rich end of the binary alloy phase diagrams. Available thermodynamic and tracer diffusion data shed further light on alloy behavior. Eight alloying elements were selected for these studies, with five elements from groups 5 and 6, two from group 8, and one from group 11 of the periodic table. They are respectively V, Nb, Ta, Cr, Mo, Fe, Ru, and Ag. The progress of precipitation in approximately 500-nm-thick alloy films, containing 2.5–3.8 at. % solute, was followed with in situ resistance and stress measurements as well as with in situ synchrotron x-ray diffraction. In addition, texture analysis and transmission electron microscopy were used to investigate the evolution of microstructure and texture of Cu(Ta) and Cu(Ag). For all eight alloys, dissociation occurred upon heating, with the rejection of solute and evolution of microstructure often occurring in multiple steps that range over several hundred degrees between approximately 100 and 900 °C. However, in most cases, substantial reductions in resistivity of the films took place below 400 °C, at temperatures of interest to copper metallization schemes for silicon chip technology.