Effect of samarium doping on the nucleation of fcc-aluminum in undercooled liquids

Sun, Yang; Zhang, Feng; Yang, Lin; Ye, Zhuo; Song, Hantao; Mendelev, Mikhail I.; Wang, Cai‐Zhuang; Ho, Kai‐Ming

doi:10.1016/j.scriptamat.2018.06.001

Cited by 8 publications

(7 citation statements)

References 50 publications

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“…Figure 3 summarizes the nucleation rate data for the Al-Sm alloys obtained in Ref. [46] and the data for the Al-Mg obtained within the present study. At very small dopant concentrations (up to 1 at.…”

Section: Effects Of Dopants On the Nucleation Ratementioning

confidence: 68%

Effects of dopants on the glass forming ability in Al-based metallic alloy

Sun

Zhang

Yang

et al. 2019

Phys. Rev. Materials

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The effect of dopants on the metallic glass forming ability is usually considered based on the analysis of changes in the liquid structure or thermodynamics. What is missing in such considerations is an analysis of how a dopant changes the properties of the crystal phases which can form instead of the glass. In order to illuminate this aspect we performed molecular dynamics simulations to study the effects of Mg and Sm dopants on the crystal nucleation in Al. The simulation data were found to be consistent with the experimental observations that addition of Mg to Al does not lead to vitrification but addition of only 8% Sm does. The significant effect of Sm doping was related to the intolerance of Al to this dopant. This leads to increase in the solid-liquid interfacial free energy, and therefore, to increase in the nucleation barrier and to a dramatic decrease in the nucleation rate. The intolerance mechanism also significantly affects the growth kinetics.The effect of dopants on the metallic glass forming ability is usually considered based on the analysis of changes in the liquid structure or thermodynamics. What is missing in such considerations is an analysis of how a dopant changes the properties of the crystal phases which can form instead of the glass. In order to illuminate this aspect we performed molecular dynamics simulations to study the effects of Mg and Sm dopants on the crystal nucleation in Al. The simulation data were found to be consistent with the experimental observations that addition of Mg to Al does not lead to vitrification but addition of only 8% Sm does. The significant effect of Sm doping was related to the intolerance of Al to this dopant. This leads to increase in the solid-liquid interfacial free energy, and therefore, to increase in the nucleation barrier and to a dramatic decrease in the nucleation rate. The intolerance mechanism also significantly affects the growth kinetics.

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Section: Effects Of Dopants On the Nucleation Ratementioning

confidence: 68%

Effects of dopants on the glass forming ability in Al-based metallic alloy

Sun

Zhang

Yang

et al. 2019

Phys. Rev. Materials

Self Cite

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“…Figure 3 summarizes the nucleation rate data for the Al-Sm alloys obtained in Ref. [42] and the data for the Al-Mg obtained within the present study. At very small dopant concentrations (up to 1 at.%) the effects of both dopants are about the same.…”

Section: Effects Of Dopants On the Nucleation Ratementioning

confidence: 68%

Effects of dopants on the glass forming ability in Al-based metallic alloy

Sun,

Zhang,

Yang

et al. 2018

Preprint

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The effect of dopants on the metallic glass forming ability is usually considered based on analysis of changes in the liquid structure or thermodynamics. What is missing in such considerations is an analysis of how a dopant changes the properties of the crystal phases which can form instead of the glass. In order to illuminate this aspect we performed molecular dynamics simulations to study the effects of Mg and Sm dopants on the crystal nucleation in Al. The simulation data were found to be consistent with the experimental observations that addition of Mg to Al does not lead to vitrification but addition of only 8% Sm does. The significant effect of Sm doping was related to the intolerance of Al to this dopant. This leads to increase in the solid-liquid interfacial free energy, and therefore, to increase in the nucleation barrier and to dramatic decrease in the nucleation rate. The intolerance mechanism also significantly affects the growth kinetics.

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“…The PEM utilizes the main CNT concept that a homogeneous nucleation happens via the formation of the critical nucleus in an undercooled liquid. The nucleation process can be efficiently sampled in the PEM by preventing a small crystal embryo consisting of N 0 atoms ( N 0 ≪ N *) from melting using external spring forces. ,, Very long ineffective simulations, in which the system is very far away from forming the critical nucleus, are avoided in this method. As the embryo grows, the harmonic potential is gradually weakened and is completely removed when the cluster size reaches a subcritical threshold, N sc ( N 0 < N sc < N *).…”

Section: Methodsmentioning

confidence: 99%

“…The nucleation process can be efficiently sampled in the PEM by preventing a small crystal embryo consisting of N 0 atoms (N 0 ≪ N*) from melting using external spring forces. 27,28,39 Very long ineffective simulations, in which the system is very far away from forming the critical nucleus, are avoided in this method. As the embryo grows, the harmonic potential is gradually weakened and is completely removed when the cluster size reaches a subcritical threshold, N sc (N 0 < N sc < N*).…”

Section: Methodsmentioning

confidence: 99%

“…In this method, a subcritical crystal nucleus is inserted in the liquid and kept from melting by springs which are gradually removed once the nucleus reaches a threshold size which is still smaller than the critical size. With this method, even the nucleation in glass forming metallic alloys can be studied. − The outcome of the MD simulation in the PEM is the critical nucleus size, N *, and shape factor, s * (which will be defined in Section ). Along with the bulk thermodynamic driving force, Δμ, this information is sufficient to get the nucleation rates using the CNT.…”

Section: Introductionmentioning

confidence: 99%

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Competitive B2 and B33 Nucleation during Solidification of Ni₅₀Zr₅₀ Alloy: Molecular Dynamics Simulation and Classical Nucleation Theory

et al. 2019

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We investigated the homogenous nucleation of the stoichiometric B2 and B33 phases in the Ni50Zr50 alloy using the persistent embryo method and the classical nucleation theory. The two phases become very close competitors at large supercoolings, which is consistent with the experimental observations. In the case of the B2 phase, the linear temperature dependence of the solid-liquid interface (SLI) free energy extrapolated to the melting temperature leads to the same value as the one obtained from the capillarity fluctuation method (CFM). In the case of the B33 phases, the SLI free energy is also a linear function of temperature at large supercoolings but the extrapolation to the melting temperature leads to a value which is considerably different from the CFM value. This is consistent with the large anisotropy of the SLI properties of the B33 phase nearby the melting temperature observed in the simulation of the nominally flat interface migration.

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Effect of samarium doping on the nucleation of fcc-aluminum in undercooled liquids

Cited by 8 publications

References 50 publications

Effects of dopants on the glass forming ability in Al-based metallic alloy

Effects of dopants on the glass forming ability in Al-based metallic alloy

Effects of dopants on the glass forming ability in Al-based metallic alloy

Competitive B2 and B33 Nucleation during Solidification of Ni₅₀Zr₅₀ Alloy: Molecular Dynamics Simulation and Classical Nucleation Theory

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Effect of samarium doping on the nucleation of fcc-aluminum in undercooled liquids

Cited by 8 publications

References 50 publications

Effects of dopants on the glass forming ability in Al-based metallic alloy

Effects of dopants on the glass forming ability in Al-based metallic alloy

Effects of dopants on the glass forming ability in Al-based metallic alloy

Competitive B2 and B33 Nucleation during Solidification of Ni50Zr50 Alloy: Molecular Dynamics Simulation and Classical Nucleation Theory

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Product

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Competitive B2 and B33 Nucleation during Solidification of Ni₅₀Zr₅₀ Alloy: Molecular Dynamics Simulation and Classical Nucleation Theory