The effect of composition on marker movement and kirkendall porosity in ternary alloys

Son, Yoon-Ho; Morral, J. E.

doi:10.1007/bf02666665

Cited by 13 publications

(7 citation statements)

References 10 publications

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“…It is found that, after annealing, Cu and Ni elements are uniformly distributed among each other as shown by the EDX mapping of the struts of the foams in Figure 2 The formation of micropores at the interface of Cu−Ni is a hallmark of the so-called Kirkendall effect, which is attributed to the significantly higher diffusion rates of Cu atoms compared to that of Ni at an elevated temperature. 33,34 Our further quantitative analysis supports this mechanism well. The diffusion coefficients (D) of Ni and Cu atoms can be determined with the Arrhenius expression given by D = C•e −E/RT , where the diffusion constants (C) are 0.78, 2.7, 0.57, and 1.77 cm 2 /s for Cu-in-Cu, Ni-in-Cu, Cu-in-Ni, and Ni-in-Ni, respectively.…”

Section: ■ Introductionsupporting

confidence: 77%

“…Mesoscopically, the distinct diffusion rates of Cu and Ni result in a net mass flow from the Cu-enriched region to the Ni-enriched region in the struts of Ni–Cu alloy foams, which is equivalent to a net flow of vacancies in the opposite direction. With sufficient time, the vacancies in the Cu-enriched area accumulate and eventually coalesce into larger micropores that reduce the total surface energy driven by thermodynamics. , In previous research, substantial efforts have been devoted to reducing porosity resulting from such a Kirkendall effect because it significantly impairs the mechanical integrity of materials as well as their thermal and electrical conductivities. However, in this work, we made the first attempt to strategically leverage the Kirkendall effect to create a new level of porosity in the entire 3D Ni foams.…”

Section: Resultsmentioning

confidence: 99%

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Kirkendall Effect in Creating Three-Dimensional Metal Catalysts for Hierarchically Porous Ultrathin Graphite with Unique Properties

Guo

Chan

et al. 2017

Chem. Mater.

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In this work, we report an innovative mechanism, the Kirkendall effect, in creating three-dimensional (3D) microporous catalysts with tunable pore sizes for the growth of hierarchic ultrathin graphite foams (HP-UGFs) with unique properties. Employing the Kirkendall effect is one of the first demonstrated for fabricating 3D porous catalysts, where tunable pores of 1.9–8.3 μm are created on 3D interconnected struts (∼100 μm). With the catalysts, we readily synthesized freestanding HP-UGFs that offer higher crystallinity and electric conductivity, larger surface area, as well as enhanced electric invariance to strains compared to those of conventional ultrathin graphite foams. A gauge factor as low as ∼10 at a strain as high as 80% is achieved owing to the unique porous corrugations created on the microstruts of the HP-UGFs. This work may inspire a new paradigm in designing and synthesizing a new type of 3D porous architecture made of 2D materials with controlled local corrugations, which could greatly benefit flexible electronics.

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Section: ■ Introductionsupporting

confidence: 77%

Section: Resultsmentioning

confidence: 99%

Kirkendall Effect in Creating Three-Dimensional Metal Catalysts for Hierarchically Porous Ultrathin Graphite with Unique Properties

Guo

Chan

et al. 2017

Chem. Mater.

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“…i¼1 X i j i ðt; ÀKÞ: ½13 The second equality in Eq. [13] can be treated also as an assumption on the boundary evolutions j i . On the other hand, Eqs.…”

Section: Modelingmentioning

confidence: 99%

“…Kirkendall's discovery, further quantified by Darken, plays an important role in formulating the basis of the theory of interdiffusion in multicomponent material, i.e., the vacancy-dependent diffusion mechanism and convection. [11][12][13] In the Darken method, an isothermal isobaric process of diffusional mixing of the components in a closed system is described. It is assumed that the diffusion takes place in one direction, diffusion in one dimension.…”

Section: Introductionmentioning

confidence: 99%

Compendium About Multicomponent Interdiffusion in Two Dimensions

Bożek

Sapa

Tkacz–Śmiech

et al. 2021

Metall Mater Trans A

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Interdiffusion between dissimilar solids can change the properties of joined materials. Although much work has been done to study experimentally and theoretically interdiffusion in one-dimensional (1-D) diffusion couples, studying interdiffusion in two-dimensional (2-D) or three-dimensional (3-D) solids remains a challenge. In this article, we report an experiment and develop a model to study interdiffusion in a multicomponent system of 2-D geometry. The results (concentration maps and profiles) are compared with data obtained by modeling and numerical simulations. It is assumed that the system satisfies Vegard’s rule and diffusion coefficients are composition dependent. To model the multidimensional diffusion with a drift, we take benefit of the concept of the drift potential. A nonlinear parabolic-elliptic system of strongly coupled differential equations is formulated and the implicit difference method, preserving Vegard’s rule, is applied in the simulations.

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“…For example, the appearance of extrema in the penetration curves-a phenomena that was first recognized in careful multicomponent diffusion experiments-is well accounted for using the square-root diffusivity method. Quantitative predictions of multicomponent effects using the square-root diffusivity method, particularly the forms of the penetration curves, have been checked against experiments, with generally good results [18,19,20,21]. Moreover, several schemes for classifying the forms of multicomponent penetration curves and their associated diffusion paths for a given diffusion couple have been discussed by Gupta and Cooper [22], Thompson and Morral [1], [2], and by Stalker and Morral [23].…”

Section: Defect and Diffusion Forum Vols 237-240 231mentioning

confidence: 99%

Analyzing Linear Multicomponent Diffusion Phenomena

Lupulescu

Glicksman

Kailasam³

2005

DDF

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We developed a MatLab c code that implements the multicomponent diffusion approaches outlined by Morral and Thompson [1,2] and by Glicksman and Lupulescu [3]. Zero flux planes (ZFP's), first introduced by Dayananda and Kim [4], occur commonly in ternary and higher-order multicomponent alloys. ZFP's for a component manifest as stationary or symmetrically moving planes disposed about the Matano interface. In contrast to the normal global mixing that occurs in a binary diffusion couple, the presence of a stationary ZFP requires that mixing of the blocked component occurs unilaterally through the release of pairs of coupled depletion-repletion waves that increase the average concentration in the component-poor alloy, but decrease it in the component-rich alloy [3]. We previously analyzed the kinetics of multicomponent diffusion near ZFP's for single-phase couples based on the behavior of diffusion couples between the fixed end-member alloy Cr-10 at.%, Al-10 at.%, Ni-80 at.%, with a series of end-member alloys having a concentration difference vector with a magnitude of 1 at.%. It was demonstrated that the spreading rates of the ternary diffusion zones could be reduced by choosing the orientation of the composition vectors in composition space to be near the Euler angle for the minor eigenvector of the diffusivity matrix. Moreover, a critical Euler angle, ψ * ≈ 29 • , was found in ternary Cr-Al-Ni alloys, near which diffusion couples selected with their composition vectors within ±5 • of ψ * exhibit minimal rates of interdiffusion [3]. The reduced atomic transport predicted in these alloys was associated with the proximity of their Euler angles to that of the ZFP for the major elemental component. Similar analyses performed on ternary couples with the fixed end member alloy Ni-43.5 at.%, Zn-25 at.%, Cu-31.5 at.% and unit composition vectors, show that diffusive spreading is reduced for couples located in composition space close to the ZFP of the minor component.

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The effect of composition on marker movement and kirkendall porosity in ternary alloys

Cited by 13 publications

References 10 publications

Kirkendall Effect in Creating Three-Dimensional Metal Catalysts for Hierarchically Porous Ultrathin Graphite with Unique Properties

Kirkendall Effect in Creating Three-Dimensional Metal Catalysts for Hierarchically Porous Ultrathin Graphite with Unique Properties

Compendium About Multicomponent Interdiffusion in Two Dimensions

Analyzing Linear Multicomponent Diffusion Phenomena

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