Stabilization of metallic emulsions by in-situ precipitating intermetallic layers

Nagy, Orsolya Z.; Szabó, János; Kaptay, George

doi:10.1016/j.intermet.2012.03.048

Cited by 9 publications

(5 citation statements)

References 48 publications

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“…This method would effectively retrain liquid phase segregation to obtain immiscible alloys with refined microstructure. Budai and Kaptay [21] and Nagy et al [22] presented the homogenous microstructure of Al-Cd alloys by in situ precipitating intermetallic Al 4 Sr compounds. The intermetallic precipitates prefer to exist at the Al-Cd interface and to stabilize the Cd droplets in the Al matrix.…”

Section: Introductionmentioning

confidence: 99%

Effect of Rare-Earth Ce on Macrosegregation in Al-Bi Immiscible Alloys

Man

Zhang

et al. 2016

Metals

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Liquid phase segregation of immiscible alloys has been investigated for decades. In this work, rare-earth Ce was studied as an additive for Al-Bi immiscible alloys. The addition of Ce restrained liquid phase segregation to obtain a uniformly dispersive microstructure. The experimental results indicated that in situ-precipitated intermetallic CeBi 2 compound acted as an inoculant for the heterogeneous nucleation of the Bi-rich droplets. The Bi-rich droplets nucleated on the CeBi 2 compound surface-a homogenous dispersed microstructure obtained via a heterogeneous nucleation route. We concluded that gravity segregation can be suppressed by the addition of rare-earth Ce.

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Section: Introductionmentioning

confidence: 99%

Effect of Rare-Earth Ce on Macrosegregation in Al-Bi Immiscible Alloys

Man

Zhang

et al. 2016

Metals

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“…The in situ method would address the challenge to obtain well-dispersed minority phase in the manufacturing of immiscible alloy. This method can overcome the poor wettability associated with the traditional ex situ reaction methods and obtain a clean interface [16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Effect of in situ phases on microstructure and properties in Al–Bi immiscible alloy

Man

Zhang

et al. 2020

Materials Science and Technology

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Al–Bi immiscible alloy is of particular interest as potential self-lubricating wear materials with a homogeneous distribution of minority phase. However, it is difficult to obtain a homogeneous microstructure by conventional casting methods due to liquid phase separation of Al–Bi immiscible alloy. We have developed a new strategy to restrain liquid phase separation and improve the properties of Al–Bi immiscible alloy by in situ phases. The in situ AlB2 phase acts as heterogeneous nucleation site to accelerate the nucleation and slow down the velocity of the Bi-rich droplet, resulting in a significant size reduction and a homogeneous microstructure of Al–Bi immiscible alloy. The self-lubricating wear resistance of Al–Bi immiscible alloy can be further enhanced by in situ Al2Cuphase.

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“…Emulsions are one of the important classes of multiphase materials. − Usually, they are considered thermodynamically unstable because of their high inner interfacial area and can be stabilized only kinetically, for example, using particles. − However, this general view is challenged by numerous observations on spontaneous emulsification. − These observations hold a promise for thermodynamically stable emulsions.…”

Section: Introductionmentioning

confidence: 99%

On the Negative Surface Tension of Solutions and on Spontaneous Emulsification

Kaptay

2017

Langmuir

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The condition of negative surface tension of a binary regular solution is discussed in this paper using the recently reconfirmed Butler equation (Langmuir 2015, 31, 5796-5804). It is shown that the surface tension becomes negative only for solutions with strong repulsion between the components. This repulsion for negative surface tension should be so strong that this phenomenon appears only within a miscibility gap, that is, in a two-phase region of macroscopic liquid solutions. Thus, for a macroscopic solution, the negative surface tension is possible only in a nonequilibrium state. However, for a nano-solution, negative surface tension is also possible in equilibrium state. It is also shown that nano- and microemulsions can be thermodynamically stable against both coalescence and phase separation. Further, the thermodynamic theory of emulsion stability is developed for a three-component (A-B-C) system with A-rich droplets dispersed in a C-rich matrix, separated by the segregated B-rich layer (the solubility of B is limited in both A and C while the mutual solubility of A and C is neglected). It is shown that when a critical droplet size is achieved by forced emulsification, it is replaced by spontaneous emulsification and the droplet size is reduced further to its equilibrium value. The existence of maximum temperature of emulsion stability is shown. Using low-energy emulsification below this maximum temperature, spontaneous emulsification can appear, which is enhanced with further decrease of temperature. This finding can be applied to interpret the experimental observations on spontaneous emulsification or for the design of stable micro- and nanoemulsions.

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Stabilization of metallic emulsions by in-situ precipitating intermetallic layers

Cited by 9 publications

References 48 publications

Effect of Rare-Earth Ce on Macrosegregation in Al-Bi Immiscible Alloys

Effect of Rare-Earth Ce on Macrosegregation in Al-Bi Immiscible Alloys

Effect of in situ phases on microstructure and properties in Al–Bi immiscible alloy

On the Negative Surface Tension of Solutions and on Spontaneous Emulsification

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