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- Discipline
- Keyword
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- Rapid solidification (8)
- Partition coefficient (6)
- Solute segregation (4)
- Heat mass transport (3)
- Segregation (3)
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- Diffusionless solidification (2)
- Extended thermodynamics (2)
- Local non-equilibrium diffusion (2)
- Material science (2)
- Binary alloys; solute trapping; rapid solidification; local-nonequilibrium diffusion; hyperbolic diffusion equation; solute concentration; solute flux fields (1)
- Colloidal solidification (1)
- Colloidal suspensions (1)
- Dendrite (1)
- Diffusion in polymers (1)
- Discrete models (1)
- Heat-mass transport (1)
- Hyperbolic heat conduction; local-nonequilibrium effects; melting; overheating; pulse heating; Stefan problem; ultrafast heat transport. (1)
- Laser heating (1)
- Local non equilibrium heat and mass transfer (1)
- Local non-equilibrium (1)
- Local non-equilibrium phase boundaries phase (1)
- Local nonequilibrium (1)
- Local nonequilibrium diffusion (1)
- Local nonequilibrium heat-mass transfer (1)
- Local nonequilibrium traveling waves (1)
- Non local diffusion (1)
- Non local heat conduction (1)
- Solute trapping; Rapid solidification; Local non-equilibrium diffusion; Hyperbolic diffusion equation (1)
- Stefan problem (1)
- Two temperature system (1)
Articles 1 - 21 of 21
Full-Text Articles in Physical Sciences and Mathematics
Rapid Phase Transformation Under Local Non-Equilibrium Diffusion Conditions, Sergey Sobolev
Rapid Phase Transformation Under Local Non-Equilibrium Diffusion Conditions, Sergey Sobolev
Sergey Sobolev
Phase transformation with a moving interface occurs under far from local equilibrium conditions when the interface moves with sufficiently high velocity. This deviation cannot be adequately described by the classical irreversible thermodynamics with diffusion equation of parabolic type because it assumes local equilibrium hypothesis. The local non-equilibrium diffusion model has been developed to take into account the deviation from local equilibrium during binary alloy solidification using the hyperbolic diffusion equation. The model introduces a finite propagation velocity of concentration disturbances in the bulk liquid VD as the characteristic diffusion parameter and predicts a sharp transition from diffusion controlled to diffusionless …
New Interpretation Of Experimental Data On Si−As Alloy Solidification With Planar Interface, Sergey Sobolev
New Interpretation Of Experimental Data On Si−As Alloy Solidification With Planar Interface, Sergey Sobolev
Sergey Sobolev
No abstract provided.
Nonlocal Diffusion Models: Application To Rapid Solidification Of Binary Mixtures, Sergey Sobolev
Nonlocal Diffusion Models: Application To Rapid Solidification Of Binary Mixtures, Sergey Sobolev
Sergey Sobolev
Various theoretical treatments and models for nonlocal diffusion are briefly reviewed and discussed. The nonlocal effects arise in far from equilibrium processes, which involve extremely fast heat and mass transfer at very small time and length scales. With only diffusive dynamics, the nonlocal models result in a set of transfer equations of parabolic type with an infinite velocity of diffusive disturbances. With the wavelike dynamics, the models lead to a set of transfer equations of hyperbolic type with a finite velocity of diffusive disturbances. Rapid solidification of binary alloys has been used to illustrate the influence of the nonlocal diffusion …
Diffusion-Stress Coupling In Liquid Phase During Rapid Solidification Of Binary Mixtures, Sergey Sobolev
Diffusion-Stress Coupling In Liquid Phase During Rapid Solidification Of Binary Mixtures, Sergey Sobolev
Sergey Sobolev
An analytical model has been developed to describe the diffusion-viscous stress coupling in the liquid phase during rapid solidification of binary mixtures. The model starts with a set of evolution equations for diffusion flux and viscous pressure tensor, based on extended irreversible thermodynamics. It has been demonstrated that the diffusion-stress coupling leads to non-Fickian diffusion effects in the liquid phase. With only diffusive dynamics, the model results in the nonlocal diffusion equations of parabolic type, which imply the transition to complete solute trapping only asymptotically at an infinite interface velocity. With the wavelike dynamics, the model leads to the nonlocal …
On The Transition From Diffusion-Limited To Kinetic-Limited Regimes Of Alloy Solidification, Sergey Sobolev
On The Transition From Diffusion-Limited To Kinetic-Limited Regimes Of Alloy Solidification, Sergey Sobolev
Sergey Sobolev
An abrupt transition from diffusion-limited solidification to diffusionless, kinetic-limited solidification with complete solute trapping is explained as a critical phenomenon which arises due to local non-equilibrium diffusion effects in the bulk liquid. The transition occurs when the interface velocityVpasses through the critical pointV=VD, where V=VDis the bulk liquid diffusive velocity. Analytical expressions are developed for velocity–temperature and velocity–undercooling functions, using local non-equilibrium partition coeffi-cient based on the Jackson et al. kinetic model and the local non-equilibrium diffusion model of Sobolev. The calculated functions dem-onstrate a sharp break in the velocity–undercooling and velocity–temperature relationships at the critical pointV=VD. At this point …
Local Nonequilibrium Solute Trapping Model For Non-Planar Interface, Sergey Sobolev
Local Nonequilibrium Solute Trapping Model For Non-Planar Interface, Sergey Sobolev
Sergey Sobolev
A generalized solute trapping model was proposed incorporating the dependency on interfacial normal velocity along the dendrite side, as an extension of the continuous growth model modified by Sobolev with the local nonequilibrium diffusion model (LNDM). The present model predicts that the transition to diffusionless solidification is not sharp, but occurs in a range of velocities. Analysis indicates that for local nonequilibrium solute diffusion in bulk liquid the effect of the interfacial normal velocity dependency on solute partitioning is considerable.
Local Non-Equilibrium Diffusion Model For Solute Trapping During Rapid Solidification, Sergey Sobolev
Local Non-Equilibrium Diffusion Model For Solute Trapping During Rapid Solidification, Sergey Sobolev
Sergey Sobolev
A local non-equilibrium diffusion model (LNDM) for rapid solidification of binary alloys has been briefly reviewed and used to modify a number of solute trapping models with different solid–liquid interface kinetics. The LNDM takes into account deviation from local equilibrium of a solute diffusion field in bulk liquid on the basis that the exact solutions to hyperbolic diffusion equations govern the solute concentration and solute flux in bulk liquid under local non-equilibrium conditions. The LNDM leads to a velocity-dependent effective diffusion coefficient in bulk liquid ahead of the solid–liquid interface, which goes to zero when the interface velocity goes to …
Rapid Colloidal Solidifications Under Local Nonequilibrium Diffusion Conditions, Sergey Sobolev
Rapid Colloidal Solidifications Under Local Nonequilibrium Diffusion Conditions, Sergey Sobolev
Sergey Sobolev
Partition coefficient for rapid solidification of colloidal suspensions has been calculated under local nonequilibrium diffusion conditions typically used when processing advanced materials. It has been demonstrated that the local nonequilibrium diffusion effects stabilize the planar solid liquid interface and lead to an abrupt transition to diffusionless solidification with complete particle trapping. The effective diffusion coefficient, which depends on interface velocity and particle size, has been introduced. It explains the strong dependences of the partition coefficient and the velocity leading to absolute stability of a planar solid–liquid interface on particle size.
An Analytical Model For Local-Nonequilibrium Solute Trapping During Rapid Solidification, Sergey Sobolev
An Analytical Model For Local-Nonequilibrium Solute Trapping During Rapid Solidification, Sergey Sobolev
Sergey Sobolev
Updated version of local non-equilibrium diffusion model (LNDM) for rapid solidification of binary alloys was considered. The LNDM takes into account deviation from local equilibrium of solute concentration and solute flux fields in bulk liquid. The exact solutions for solute concentration and flux in bulk liquid were obtained using hyperbolic diffusion equations. The results show the transition from diffusion-limited to purely thermally controlled solidification with effective diffusion coefficient D →0 and complete solute trapping K(v)→1 at V→VDb for any kind of solid-liquid interface kinetics. Critical parameter for diffusionless solidification and complete solute trapping is the diffusion speed in bulk liquid …
Diffusion Of Low Molecular Mass Substances In Glassy Polymers, Sergey Sobolev
Diffusion Of Low Molecular Mass Substances In Glassy Polymers, Sergey Sobolev
Sergey Sobolev
No abstract provided.
Local Nonequilibrium Transport Models, Sergey Sobolev
Local Nonequilibrium Transport Models, Sergey Sobolev
Sergey Sobolev
No abstract provided.
Local Non-Equilibrium Diffusion Effects On The Kinetic Phase Boundaries In Solidification, Sergey Sobolev
Local Non-Equilibrium Diffusion Effects On The Kinetic Phase Boundaries In Solidification, Sergey Sobolev
Sergey Sobolev
No abstract provided.
Effects Of Local Non-Equilibrium Solute Diffusion On Rapid Solidification Of Alloys, Sergey Sobolev
Effects Of Local Non-Equilibrium Solute Diffusion On Rapid Solidification Of Alloys, Sergey Sobolev
Sergey Sobolev
A conceptual foundation for the study of local non-equilibrium solute diffusion under rapid solidifica- tion conditions is proposed. The model takes into account the relaxation to local equilibrium of the solute flux and incorporates two diffusion speeds, VDb, the bulk liquid diffusion speed, and VDi, the interface diffusive speed, as the most important parameters governing the solute concentration in the liquid phase and solute partitioning. The analysis of the model predicts complete solute trapping and the transition to a purely thermally controlled solidification, which occur abruptly when the interface velocity V equals the bulk liquid diffusion speed VDb. The abrupt …
The Local-Nonequilibrium Temperature Field Around The Melting And Crystallization Front Induced By Picosecond Pulsed Laser Irradiation, Sergey Sobolev
The Local-Nonequilibrium Temperature Field Around The Melting And Crystallization Front Induced By Picosecond Pulsed Laser Irradiation, Sergey Sobolev
Sergey Sobolev
The local-nonequilibrium model for heat transport around melting and crystallization zone induced by ultrafast laser irradiation is considered. The model predicts strong overheating during melting of the material near the interface. Moreover, the local-nonequilibrium effects lead to an interface temperature gradient steeper than expected from the classical heat flow calculations. Possible modification of the kinetics of melting to include the relaxation effects is also discussed.
Applications Of Extended Thermodynamics ...Part Iii., Sergey Sobolev
Applications Of Extended Thermodynamics ...Part Iii., Sergey Sobolev
Sergey Sobolev
No abstract provided.
Local Non-Equilibrium Model For Rapid Solidification Of Undercooled Melts, Sergey Sobolev
Local Non-Equilibrium Model For Rapid Solidification Of Undercooled Melts, Sergey Sobolev
Sergey Sobolev
No abstract provided.
Two Temperature Stefan Problem, Sergey Sobolev
Applications Of Extended Thermodynamics ...Part I., Sergey Sobolev
Applications Of Extended Thermodynamics ...Part I., Sergey Sobolev
Sergey Sobolev
No abstract provided.
Applications Of Extended Thermodynamics ...Part Ii., Sergey Sobolev
Applications Of Extended Thermodynamics ...Part Ii., Sergey Sobolev
Sergey Sobolev
No abstract provided.
Two-Temperature Discrete Model For Nonlocal Heat Conduction, Sergey Sobolev
Two-Temperature Discrete Model For Nonlocal Heat Conduction, Sergey Sobolev
Sergey Sobolev
The two-temperature discrete model for heat conduction in heterogeneous media is proposed. It is shown that the discrete model contains as limiting cases both hyperbolic and parabolic heat conduction equations for propagative and diffusive regimes, respectively. To obtain these limiting cases two different laws of continuum limit have been introduced. The evolution of the two-temperature system comprises three stages with distinct time scales : fast relaxation of each subsystem to local equilibrium, energy exchange between the subsystems and classical hydrodynamics.
Transport Processes And Traveling Waves In Systems With Local Nonequilibrium, Sergey Sobolev
Transport Processes And Traveling Waves In Systems With Local Nonequilibrium, Sergey Sobolev
Sergey Sobolev
No abstract provided.