Molecular dynamics study of melting, diffusion, and sintering of cementite chromia core–shell particles

Gao, Yawei; Pastrana, Ana Paula Clares; Manogharan, Guha; Duin, Adri C. T. van

doi:10.1016/j.commatsci.2021.110721

Cited by 7 publications

(4 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The smooth bond-order transition for bond formation and dissociation enables ReaxFF reactive force field method to describe chemical reactions. Moreover, the electronegativity equalization method (EEM) is employed by ReaxFF to dynamically calculate the atomic charges. − More details about ReaxFF are available in previously published literature. ,− …”

Section: Methodsmentioning

confidence: 99%

C/H/O/F/Al ReaxFF Force Field Development and Application to Study the Condensed-Phase Poly(vinylidene fluoride) and Reaction Mechanisms with Aluminum

et al. 2022

Self Cite

View full text Add to dashboard Cite

Poly(vinylidene fluoride) (PVDF) is a well-known polymer with a (−CH2–CF2−) n chemical formula that is used, in particular, in electronic devices. The spatial arrangements of −CH2– and −CF2– units and the spatial alignment of PVDF chains determine the ferroelectricity, pyroelectricity, and piezoelectricity of condensed-phase PVDF. PVDF can be fabricated with Al metal as an energetic composite for rocket propellants. To better understand how PVDF molecular structures affect the properties in the condensed phase and the chemical reaction mechanisms with Al, we have developed a C/H/O/Al/F ReaxFF force field through parameterization against data from quantum mechanical (QM) calculations and experiments. This ReaxFF force field demonstrates good transferability in both low-temperature regimes, dominated by nonreactive conformational changes, and high-temperature regimes, dominated by PVDF chemical conversion. In the low-temperature regime, we investigated the α → β crystalline phase transition kinetics induced by a poling electric field or mechanical deformation. The molecular dynamics (MD) simulations show that electric field magnitude thresholds for the α → β crystalline phase transitions are 5.0 and 7.5 GV/m in the y and x directions, respectively. In addition, we found that the trans-gauche+–trans-gauche– conformation in the α crystalline structure transforms to the all-trans conformation through mechanical deformation. However, the all-trans chains are arranged in an antiparallel pattern in the stretched structure, resulting in zero polarity. We also observed that the poling electric field threshold can be reduced by combining it with mechanical deformation. In the high-temperature regime, we analyzed the reactions between PVDF and surface-oxidized Al nanoparticles. Results indicate that the reactions are triggered by the absorption of an H or F atom from PVDF to the alumina surface, followed by HF formation from PVDF pyrolysis. The produced HF molecules rapidly react with the surface alumina to form OH and AlF x . The activation energy of AlF x formation is estimated using Arrhenius analysis. In addition, OH groups combine to produce H2O vapor, whereas AlF x aggregates. Moreover, AlC x is also produced. The developed C/H/O/F/Al ReaxFF force field can serve for future studies of composite materials involving Al, alumina, PVDF, and its copolymers.

show abstract

Section: Methodsmentioning

confidence: 99%

C/H/O/F/Al ReaxFF Force Field Development and Application to Study the Condensed-Phase Poly(vinylidene fluoride) and Reaction Mechanisms with Aluminum

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…This force field has been successfully applied in studying pure chromia particles and chromia coated cementite particles. 43,44 With this force field, we perform MD simulations with a Berendsen thermostat 45 in the following two systems: a bi-modal particle system and a monomodal particle system. The bi-modal particle system consists of 2 coarser particles, 4 finer particles, 160 water molecules, and 100 DEG molecules, whereas the mono-modal particle system consists of 2 coarser particles, 160 water molecules, and 100 DEG molecules.…”

Section: Simulation Setupmentioning

confidence: 99%

A reactive molecular dynamics study of bi-modal particle size distribution in binder-jetting additive manufacturing using stainless-steel powders

Gao

Clares

Manogharan

et al. 2022

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Zhang et al found that when the nanoparticles were sintered at high temperature and subjected to a cooling process, the structure became more stable, and the potential residual stresses were further eliminated . Furthermore, for the sintering process, Gao et al found that the sintering in the liquid phase has four stages, including random movement and contact of two particles, shell layers intermingling, and core fuse, while the sintering in the solid phase includes the former three stages . In general, obtaining the microstructural evolution’s mechanism of coalescence behavior between clusters is essential for the preparation and control of new materials.…”

Section: Introductionmentioning

confidence: 99%

Coalescing Dynamics between Ag₅₅ and Cu₅₅ Clusters as Well as Thermodynamics during Cooling the Coalesced Clusters from Atomic Simulations

Liu

Zhang

2023

J. Phys. Chem. A

View full text Add to dashboard Cite

Molecular dynamics simulations are performed to investigate the coalescing processes between a Cu 55 cluster with a liquid, FCC, or Ih structure and a Ag 55 cluster in liquid, as well as the structural changes of the coalesced clusters during the cooling process. The simulation results show that the initial structure of the Ag and Cu clusters significantly affects the coalescence stages and the structures after coalescence. There are apparent rotations of the Ag cluster with the liquid structure relative to the Cu cluster with the liquid structure when they are approaching. Before the formation of a neck, the Cu cluster with the Ih structure is more stable and less likely to lose its structure compared to the Cu cluster with the FCC structure. During the cooling process, the coalesced clusters will form different packing structures, including Ih and metastable core/shell structures. The Lode− Nadai values reveal the loading states on the atoms when the two clusters collide. The thermodynamic behaviors during the cooling process were investigated to better understand the order degree of the packing structures and the structural transition processes.

show abstract

Molecular dynamics study of melting, diffusion, and sintering of cementite chromia core–shell particles

Cited by 7 publications

References 40 publications

C/H/O/F/Al ReaxFF Force Field Development and Application to Study the Condensed-Phase Poly(vinylidene fluoride) and Reaction Mechanisms with Aluminum

C/H/O/F/Al ReaxFF Force Field Development and Application to Study the Condensed-Phase Poly(vinylidene fluoride) and Reaction Mechanisms with Aluminum

A reactive molecular dynamics study of bi-modal particle size distribution in binder-jetting additive manufacturing using stainless-steel powders

Coalescing Dynamics between Ag₅₅ and Cu₅₅ Clusters as Well as Thermodynamics during Cooling the Coalesced Clusters from Atomic Simulations

Contact Info

Product

Resources

About

Molecular dynamics study of melting, diffusion, and sintering of cementite chromia core–shell particles

Cited by 7 publications

References 40 publications

C/H/O/F/Al ReaxFF Force Field Development and Application to Study the Condensed-Phase Poly(vinylidene fluoride) and Reaction Mechanisms with Aluminum

C/H/O/F/Al ReaxFF Force Field Development and Application to Study the Condensed-Phase Poly(vinylidene fluoride) and Reaction Mechanisms with Aluminum

A reactive molecular dynamics study of bi-modal particle size distribution in binder-jetting additive manufacturing using stainless-steel powders

Coalescing Dynamics between Ag55 and Cu55 Clusters as Well as Thermodynamics during Cooling the Coalesced Clusters from Atomic Simulations

Contact Info

Product

Resources

About

Coalescing Dynamics between Ag₅₅ and Cu₅₅ Clusters as Well as Thermodynamics during Cooling the Coalesced Clusters from Atomic Simulations