Ternary Alloy Phase Research Articles

Phase diagram calculation and predication of Au–Pd–Zr ternary system

Au–Pd–Zr ternary alloy phase diagram at 25 °C was calculated by Panda phase calculation software, and the thermodynamic data were based on three binary alloy phase diagrams: Pd–Au, Au–Zr, and Pd–Zr. Five composition points in the ternary phase diagram were selected to predict the precipitation order. One (32Au–32Pd–36Zr) of the five composition points in ternary phase diagram was chosen to verify the correctness of the phase diagram calculation and the precipitation order by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The unknown phase in XRD patterns was predicated by EDS and materials studio (MS) software. The experimental results show that there are seven key ternary reactions points and 17 phase regions in all isothermal sections at 25 °C. The thermodynamic process and microstructure for the alloy phase can be described in order according to the vertical section in phase diagram. The phase compositions of the chosen one point are consistent with calculation prediction. The unknown phase in XRD patterns should be Zr2AuPd by the first principle X-ray simulation.

Local melting in Al embedded with TiNi powder induced by microarea self-propagating high-temperature synthesis

Microarea self-propagating high-temperature synthesis (microSHS) was ignited by the heat of mixing generated at the boundaries between an Al matrix and TiNi particles during plastic deformation at room temperature. The temperature of the boundaries was rapidly increased by microSHS; the temperature elevation resulted in local melting of the TiNi particle and the surrounding Al matrix, because the heat of mixing was localized in the vicinity of the TiNi particle although the amount of the heat of mixing was limited. Since the amount of the local melting region induced by microSHS is restricted, not only major elements (i.e. Al, Ti and Ni) but also impurities were involved in the solidification followed by local melting. As a result, FeNi nanoprecipitates, which have not been reported in SHS studies, were formed by inclusion of Fe, initially included as an impurity in raw materials. The formation mechanism of FeNi nanoprecipitates is discussed based on reference to the Al–Fe–Ni ternary alloy phase diagram. It is expected that local melting induced by microSHS is a key phenomonon for amorphization during severe plastic deformation of elemental sheets.

Celebrating ASM's First 100 Years in Supporting Materials Innovation: 1994-2003

Abstract In recognition of ASM International's 100-year anniversary, AM&P highlights historic events and technological advancements that occurred over the course of those years. This issue extends the timeline from 1994 to 2003, which includes the formation of the ASM Thermal Spray Society, Heat Treating Society, and Electronic Device Failure Analysis Society, the publication of the 10-volume Handbook of Ternary Alloy Phase Diagrams, the renovation of the training center at Materials Park, the first Materials Camp, and the introduction of the Alloy Data Center.

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.

Effect of low energy He +-ion irradiation on structural and magnetic properties of thin Pt/Cr/Co multilayers

In this work, we report on the changes in structural and magnetic properties of [Pt (0.7 nm)/Cr ( x nm)/Co (0.5 nm)] ×15/Si, x = 0.1 and 0.2 nm, due to 10 keV He +-ion irradiation at room temperature in the fluence range of 2 × 10 15–5 × 10 16 ions-cm −2. Enhancement in the coercivity values with a fairly square magnetization reversal loop (for both the multilayers), upon irradiation to the fluence of 5 × 10 16 ions-cm −2 was observed. Above finding is discussed in the realm of ion beam mixing, leading to the CoCrPt ternary alloy phase formation, after low-energy He +-ion irradiation.

Effects of thermal annealing on structural and magnetic properties of thin Pt/Cr/Co multilayers

Thermal stability of thin Pt/Cr/Co multilayers and the subsequent changes in their structural, magnetic, and magneto-optical properties are reported. We observe CoCrPt ternary alloy phase formation due to annealing at temperatures about 773 K, which is accompanied by enhancement in the coercivity value. In addition, 360° domain wall superimposed on a monodomain like background has been observed in the pristine multilayer, which changes into a multidomain upon annealing at 873 K.

Co–B–Si–Ta bulk metallic glasses designed using cluster line and alloying

The formations of Co-based Co–B–Si–Ta bulk metallic glasses, as well as their mechanical and corrosion properties have been explored in this work. The alloy compositions were designed by using the cluster line approach and the alloying strategy, where the cluster line referred to a straight composition line linking a specific binary cluster to the third element in a ternary alloy phase diagram. The base ternary compositions in the Co–B–Si ternary system were first determined by the intersection points of two cluster lines, Co–B cluster to Si and Co–Si cluster to B. Then these basic ternary compositions were a small amount of Ta alloyed to further improve the glass-forming abilities. Experimental results revealed that good glass formers with 4 mm in diameter occurred at Co 62.2B 26.9Si 6.9Ta 4, obtained by Ta alloying of the base intersection compositions of Co 7B 3–Si with Co 9Si–B. This bulk metallic glass have not only high thermal stabilities with high T g and T x values, but also exhibit high fracture strength of about 4760 MPa, high Vickers hardness of about 1460, a Young's modulus of 198 GPa, and good corrosion resistances in 1 mol/L HCl and 3 mass% NaCl solutions.

Formation rule of β-FeSi2 phases in (Fe, M)Si2 ternary alloys

Binary β-FeSi2 phase is an important semiconductor metal silicide with narrow band-gaps. The formation of this phase in ternary alloys was investigated for the search of ternary semiconductor silicides. Using the cluster line approach as the theoretical guideline, a structure model is established with one cluster and one glue atom, and alloy series of Fe3Si8M(M=B, Cr, Ni, Cu, Co, Al) were designed by replacing the glue atom Fe in binary β-FeSi2. To obtain homogenous alloys, high vacuum suction casting and melt spinning method were used for the preparation of alloy rods and ribbons. Microstructure and composition analysis showed that the β phase could dissolve 15%—20% Ni, 4%—13% Cu, 7%—10%Co and 7%—10%Cr (molar content). However, in contrary to the designed formula, the added Al replaces Si rather than Fe. There were trace amounts of amorphous particles in Fe3Si8B and Fe3Si8Cr ribbon samples, which showed under the rapid cooling conditions, the addition of B and Cr was favorable for the amorphous phase formation.

Ion induced modification in structural and magnetic properties of Pt/Cr/Co multilayers

This paper reports on the change in the magnetic and the structural properties of Pt/Cr/Co multilayers due to 1 MeV N +-ion irradiation at room temperature. We observe irradiation induced formation of the CoCrPt ternary alloy phase at a fluence of 1×10 16 ions cm −2. Phase formation is accompanied by an enhancement in the coercivity. The enhancement in the coercivity is attributed to inhomogeneous alloying and possible mixing-induced strain. These findings are explained in the light of ion beam induced recoil mixing and ionization events.

Formation of long-period nanostructural phases in Ni2MnGa-based L21 alloys with thermoelastic martensitic transitions

The crystalline structures of martensite phases in Ni2MnGa-based ternary alloys have been studied in a wide range of temperatures and compositions transmission and scanning electron microscopy, X-ray diffraction, and electron diffraction. It is found that long-period nanostructural phases with thin-plate morphology are formed as a result of martensitic transformation in Ni2MnGa-based alloys.

Phase formation and changes in magnetic property of Co/Cr/ Pt multilayers

We report on CoCrPt ternary alloy phase formation and changes in magnetic properties of Co/Cr/Pt multilayers due to 1 MeV N + ion irradiation at room temperature. Irradiation induced changes occurring across the Co/Cr/Pt interfaces are studied by X-ray reflectivity, glancing angle X-ray diffraction, and magneto optical Kerr effect measurements. Irradiation induced mixing across the interface shows an enhancement in the coercivity, sufficient coercivity squareness and magnetic anisotropy. The results are discussed in the realm of ion beam induced recoil mixing across the interfaces.

Modification of the magnetic and the structural properties of Pt/Cr/Co multilayers by He+-ion irradiation

We report on the effects of 2MeV He+-ion irradiation on the magnetic and structural properties of Pt/Cr/Co multilayers. We observe He+-ion irradiation leads to mixing across the interfaces [Pt (2.5nm)/Cr (0.8nm)/Co (3.0nm)]×6/Si multilayers. In addition, we observe Co–Cr–Pt phase formation at the highest fluence of 5.5×1016ionscm−2. This is accompanied by an enhancement in the coercivity. Such enhancement in the coercivity is attributed to inhomogeneous alloying and a possible mixing-induced strain. High-resolution transmission electron microscopy confirms the formation of CoCrPt ternary alloy phase. These findings are explained in the light of ion beam induced recoil mixing and ionization events.

Effect of ion beam irradiation on magnetic and structural properties of Pt/Cr/Co multilayers

This paper discusses the effect of ion beam irradiation on the magnetic and structural properties of Pt/Cr/Co multilayers. We observe Co–Cr–Pt ternary alloy phase formation in 1MeV N+ ion irradiated [Pt (2.5nm)/Cr (0.8nm)/Co (3.0nm)]×6/Si multilayers for a fluence of 1×1016 ions cm−2 and beyond. The observed phase formation is accompanied by an enhancement in the average grain size, surface roughness and coercivity. Monte Carlo simulation has been performed to study ion-induced defect evolution and atomic displacements to correlate the above observed effects.

A cluster line approach for composition rules of quasicrystals and bulk metallic glasses

This paper analyzes the structure and composition characteristics of ternary quasicrystals and bulk metalic glasses from the viewpoint of atomic clusters. It is pointed out that quasicrystals and bulk metallic glasses satisfy a cluster line rule. The cluster line refers to a straight composition line linking a specific cluster to the third element in a ternary alloy phase diagram. A ternary quasicrystal or bulk metallic glass composition is located at the intersection point of two cluster lines. Ternary quasicrystal and bulk metallic glass compositions can be the expressed with a cluster-plus-glue-atom model which can predict new ternary bulk metallic glasses.

Intermediate phases in binary and ternary alloys: a new perspective on semi-empirical bondconstraint theory

This paper extends the scope of semi-empirical bond constraint theory, (SEBCT) and usesthis extension to provide quantitative insights into the atomic scale bonding interactionsfor the two transitions that bracket intermediate phases (IPs) in binary and ternary alloys.Reversibility windows have usually been defined in terms of the average bonding coordination,rc (also, Nav, ), and show considerable scatter between different alloys when displayed in this way. Thispaper analyzes and plots these transitions in terms of the average number of bondingconstraints/atom,nc (also Cav), and thereby provides important insights into the extent to which SEBCT must bemodified by either extending, or contracting the force field with respect to the2-body bond-stretching and 3-bond-bending valence forces of the original SEBCTformulation. These modifications include (i) broken bond-bending constraints that reducenc below the level determined from stretching and bending constraints of the SEBCT,and (ii) additional forces due to repulsions between non-bonding lone-pair orbitalson two-fold coordinated Se, three-fold coordinated As, and terminal or one-foldcoordinated I atoms that add additional constraints to the SEBCT counting. Thesemodifications identify the bonding interactions that give rise to the scatter in therc-based plots, and then use the IP plots based onrc to provide a way of determining whether broken or additional constraints move the windowthreshold, respectively above or below the SEBCT value of 2.4.

Rapid solidification and dendrite growth of ternary Fe-Sn-Ge and Cu-Pb-Ge monotectic alloys

The phase separation and dendrite growth characteristics of ternary Fe-43.9%Sn-10%Ge and Cu-35.5%Pb-5%Ge monotectic alloys were studied systematically by the glass fluxing method under substantial undercooling conditions. The maximum undercoolings obtained in this work are 245 and 257 K, respectively, for these two alloys. All of the solidified samples exhibit serious macrosegregation, indicating that the homogenous alloy melt is separated into two liquid phases prior to rapid solidification. The solidification structures consist of four phases including α-Fe, (Sn), FeSn and FeSn2 in Fe-43.9%Sn-10%Ge ternary alloy, whereas only (Cu) and (Pb) solid solution phases in Cu-35.5%Pb-5%Ge alloy under different undercoolings. In the process of rapid monotectic solidification, α-Fe and (Cu) phases grow in a dendritic mode, and the transition “dendrite→monotectic cell” happens when alloy undercoolings become sufficiently large. The dendrite growth velocities of α-Fe and (Cu) phases are found to increase with undercooling according to an exponential relation.

Peculiarities of Precipitation of Intermediate Phase in Ternary Alloys

The growth of non-stoichiometric particles of an intermediate ternary phase during the decomposition of a weakly supersaturated solution is considered. A mathematical model which describes a non-parabolic growth of precipitates and concentrations tending to asymptotic value at long times is suggested. Shape instability during the growth of the stoichiometric ternary phase based on one of the components in the supersaturated solution is investigated.

The interfacial reactions of infrared brazing Cu and Ti with two silver-based braze alloys

The microstructural evolution and shear strength of the infrared brazed Cu and Ti with two silver-based braze alloys are studied. The dissolution between the molten braze and Cu substrate is much more prominent than that of Ti substrate. For specimens infrared brazed with pure Ag, the molten braze is separated into Ag-, Cu- and Ti-rich liquids. The Ag-rich liquid overflows out of the joint, so only the liquid rich in Cu and Ti is left in the joint. The joint is primarily comprised of Cu 4Ti and Cu 2Ti phases, and three interfacial reaction layers, CuTi 2, CuTi and Cu 4Ti 3 are observed after infrared brazing. For specimens infrared brazed with 72Ag–28Cu, the microstructural evolution is well elucidated by the Ag–Cu–Ti ternary alloy phase diagram, and its shear strength is strongly related to the presence of interfacial phases between Ti and the braze alloy.

Microstructure of Electrodeposited Sn-Ag-Cu Ternary Alloys.

Composition, surface morphology and phase structure of Sn-Ag-Cu ternary alloys electrodeposited from pyrophosphate-Iodide bath under the galvanostatic conditions were examined. Contents of Ag and Cu in the deposits decreased with increasing current density. There was correlations between surface morphology of the deposits and their compositions. Composition-phase diagram of the electrodeposits corresponded to Sn-Ag-Cu ternary alloy phase diagram in the composition range with higher content of Sn.

Growth of large single-grain quasicrystals from high-temperature metallic solutions

Flux-growth techniques have been successfully applied to the preparation of several families of quasicrystals and related approximant phases. Large (up to 1cm3) single-grain samples have been obtained for icosahedral R–Mg–Zn (R=Y, Gd, Tb, Dy, Ho and Er), decagonal Al–Ni–Co, icosahedral Al–Pd–Mn, icosahedral Al–Ga–Pd–Mn, and the ξ′ Al–Pd–Mn approximant phase. The samples are obtained by slowly cooling ternary (or quaternary) melts of a composition that intersects the primary solidification surface of the desired phase in the equilibrium ternary alloy phase diagram (i.e. this is a self-flux technique). The technique clearly reveals the growth habit, and results in remarkably strain-free quasicrystals.