Thermodynamics and amorphization of the copper–zirconium alloys

Зайцев, А. И.; Zaitseva, N. E.; Alexeeva, Julia P.; Дунаев, С. Ф.; Nechaev, Yu. S.

doi:10.1039/b305089k

Cited by 30 publications

(38 citation statements)

References 50 publications

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“…Figure 4 shows the calculated dependencies of the Gibbs free energy of the amorphous phase and solid solution at 300 K. In this figure, values of the Gibbs free-energy of the Cu 9 Zr 2 , Cu 51 Zr 14 , Cu 8 Zr 3 , Cu 2 Zr, Cu 10 Zr 7 , CuZr, Cu 5 Zr 8 and CuZr 2 intermetallic compounds calculated at 1123K by Zaitsev et al [25] using the associated-solution model are reported for comparison. If the thermodynamic functions of the intermetallic compounds could have been determined at room temperature, the Gibbs free energy would have been lower.…”

Section: Thermodynamic Properties Of the Binary Cu-zr Alloysmentioning

confidence: 95%

Formation of amorphous phase in the binary Cu−Zr alloy system

Kwon

Kim²,

Kim³

et al. 2006

Met. Mater. Int.

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The aim of this work is to elucidate the formation of the amorphous phase in the Cu-Zr binary alloy system. It was found that 1 mm diameter rods with a fully amorphous structure can be prepared in a relatively wide range of compositions. In contrast, the formation of 2 mm diameter rods was achieved only for the Cu64Zr36 alloy and in the range of Cu53Zr47 -Cu50Zr50, which are compositions near the energetically stable Cu2Zr and CuZr intermetallic compounds. The difference between the calculated Gibbs free energy of the amorphous phase and the intermetallic compounds gives insight into the range of glass formation. In addition, the formation of the energetically stable phases can be kinetically by-passed owing to the crystallization of several competing phases.

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Section: Thermodynamic Properties Of the Binary Cu-zr Alloysmentioning

confidence: 95%

Formation of amorphous phase in the binary Cu−Zr alloy system

Kwon

Kim²,

Kim³

et al. 2006

Met. Mater. Int.

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“…Of course, reliable prediction and control of phase selection and structural dynamics requires quantification of system thermodynamics as well as an understanding of the kinetic mechanisms involved in solidification/devitrification processes, and advances in the thermodynamics and structure of Cu-Zr liquids, glasses, and crystalline phases recently have been reported. [11][12][13] Indeed, with numerous stable and metastable crystalline phases, this system offers an immense spectrum of potentially accessible structures and properties and has attracted much attention related to BMGs, [14][15][16] crystallization structures, [17][18][19] and ACC materials. [20,21] A review of prior thermodynamic treatments for the Cu-Zr system was reported recently, and the assessed phase diagram is shown in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

High-Accuracy X-Ray Diffraction Analysis of Phase Evolution Sequence During Devitrification of Cu50Zr50 Metallic Glass

Kalay

Kramer

Napolitano

2010

Metall Mater Trans A

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Real-time high-energy X-ray diffraction (HEXRD) was used to investigate the crystallization kinetics and phase selection sequence for constant-heating-rate devitrification of fully amorphous Cu 50 Zr 50 , using heating rates from 10 K/min to 60 K/min (10 °C/min to 60 °C/min). In situ HEXRD patterns were obtained by the constant-rate heating of melt-spun ribbons under synchrotron radiation. High-accuracy phase identification and quantitative assessment of phase fraction evolution though the duration of the observed transformations were performed using a Rietveld refinement method. Results for 10 K/min (10 °C/min) heating show the apparent simultaneous formation of three phases, orthorhombic Cu 10 Zr 7 , tetragonal CuZr 2 (C11 b ), and cubic CuZr (B2), at 706 K (433 °C), followed immediately by the dissolution of the CuZr (B2) phase upon continued heating to 789 K (516 °C). Continued heating results in reprecipitation of the CuZr (B2) phase at 1002 K (729 °C), with the material transforming completely to CuZr (B2) by 1045 K (772 °C). The Cu 5 Zr 8 phase, previously reported to be a devitrification product in C 50 Zr 50 , was not observed in the present study. Real-time high-energy X-ray diffraction (HEXRD) was used to investigate the crystallization kinetics and phase selection sequence for constant-heating-rate devitrification of fully amorphous Cu 50 Zr 50 , using heating rates from 10 K/min to 60 K/min (10°C/min to 60°C/min). In situ HEXRD patterns were obtained by the constant-rate heating of melt-spun ribbons under synchrotron radiation. High-accuracy phase identification and quantitative assessment of phase fraction evolution though the duration of the observed transformations were performed using a Rietveld refinement method. Results for 10 K/min (10°C/min) heating show the apparent simultaneous formation of three phases, orthorhombic Cu 10 Zr 7 , tetragonal CuZr 2 (C11 b ), and cubic CuZr (B2), at 706 K (433°C), followed immediately by the dissolution of the CuZr (B2) phase upon continued heating to 789 K (516°C). Continued heating results in reprecipitation of the CuZr (B2) phase at 1002 K (729°C), with the material transforming completely to CuZr (B2) by 1045 K (772°C). The Cu 5 Zr 8 phase, previously reported to be a devitrification product in C 50 Zr 50 , was not observed in the present study.

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“…where ω 2 = (cq) 2 in the numerators and the exponential coefficients given in [6], [7], and [17] depend on the parameter…”

Section: Relation Between the R-phonon Energy Spectrum Width And The mentioning

confidence: 99%

“…We use the term "R-phonon" because the denominator of the retarded Green's function d R αβ (ω, q, z, z 1 ), as well as the function D R αβ (ω, q, z, z 1 ), can be written in a form corresponding to the denominator of the retarded Green's function of free bulk phonons in an unbounded space in the frequency-momentum representation [5], [6], [17]. The Keldysh functions of free phonons in a semibounded medium D ij αβ (ω, q, z, z 1 ) can be related to the retarded Green's functions D R αβ (ω, q, z, z 1 ) by using the Planck distribution function depending only on the frequency ω analogously to the case of the Keldysh functions of free phonons in unbounded media in [4] and [18].…”

Section: Introductionmentioning

confidence: 99%

“…The expression for D R αβ is finally determined only by the retarded functions D R αβ because the functions D ij αβ are related to each other and to D R αβ in any representation and in any approximation [4]. As in the case of unbounded media in the frequency-momentum representation [3], the retarded Green's functions of free phonons in a semibounded medium in the (ω, q, z)-representation can be obtained by replacing ω with ω + iδ, δ → 0, in the Green's functions, which are solutions of the equations of motion of this medium [5], [6]. Such functions for an isotropic elastic semibounded medium were calculated in [7], where the elastic constants were terminated outside the medium surface.…”

Section: Introductionmentioning

confidence: 99%

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Rayleigh wave attenuation due to scattering by stationary defects

Zaitseva

2005

Theor Math Phys

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We obtain expressions for the energy spectrum widths of Rayleigh waves arising because of their scattering by point and distributed defects of the surface, as well as by the edge dislocations on the surface and by the grooves of a random lattice in the surface plane. The calculations are valid when the defect density is small. Under certain conditions, our results coincide with the results of other authors who studied the scattering of Rayleigh waves by point defects and by the grooves of a random lattice. The calculations are based on the Keldysh diagram technique modified for the case of semibounded media.

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Thermodynamics and amorphization of the copper–zirconium alloys

Cited by 30 publications

References 50 publications

Formation of amorphous phase in the binary Cu−Zr alloy system

Formation of amorphous phase in the binary Cu−Zr alloy system

High-Accuracy X-Ray Diffraction Analysis of Phase Evolution Sequence During Devitrification of Cu50Zr50 Metallic Glass

Rayleigh wave attenuation due to scattering by stationary defects

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