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- Rapid solidification (2)
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- Binary alloys; solute trapping; rapid solidification; local-nonequilibrium diffusion; hyperbolic diffusion equation; solute concentration; solute flux fields (1)
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- Solute trapping; Rapid solidification; Local non-equilibrium diffusion; Hyperbolic diffusion equation (1)
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Articles 1 - 6 of 6
Full-Text Articles in Physics
Structure And Dynamics Of High Temperature Superconductors, Jennifer Lynn Niedziela
Structure And Dynamics Of High Temperature Superconductors, Jennifer Lynn Niedziela
Doctoral Dissertations
High temperature superconductivity in iron based compounds has presented a series of complex problems to condensed matter physics since being discovered in 2008. The stalwart basis of condensed matter physics is the “strength in numbers" aspect of crystalline periodicity. Perfect crystalline periodicity has made possible the reduction of the questions of structural and electronic properties to single dimensions, increasing the tractability of these problems. Nevertheless, modern complex materials stretch these assumptions to their limits, and it is at this point where our work starts. Using neutron and x-ray scattering, we have conducted a series of studies on the structural disorder …
Phase Field Crystal Approach To The Solidification Of Ferromagnetic Materials, Niloufar Faghihi
Phase Field Crystal Approach To The Solidification Of Ferromagnetic Materials, Niloufar Faghihi
Electronic Thesis and Dissertation Repository
The dependence of the magnetic hardness on the microstructure of magnetic solids is investigated, using a field theoretical approach, called the Magnetic Phase Field Crystal model. We constructed the free energy by extending the Phase Field Crystal (PFC) formalism and including terms to incorporate the ferromagnetic phase transition and the anisotropic magneto-elastic effects, i.e., the magnetostriction effect. Using this model we performed both analytical calculations and numerical simulations to study the coupling between the magnetic and elastic properties in ferromagnetic solids. By analytically minimizing the free energy, we calculated the equilibrium phases of the system to be liquid, non-magnetic …
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 …
An Analytical Model For Complete Solute Trapping During Rapid Solidification Of Binary Alloys, Sergey Sobolev
An Analytical Model For Complete Solute Trapping During Rapid Solidification Of Binary Alloys, Sergey Sobolev
Sergey Sobolev
An analytical model has been developed to describe solute partitioning during rapid solidification of binary alloys under local nonequilibrium conditions. The model takes into account the deviations from equilibrium both at the solid–liquid interface according to the kinetic approach of Jackson et al. based on Monte Carlo simulations and in the bulk liquid using local nonequilibrium diffusion model (LNDM). The dimensionless growth parameter b found in the Monte Carlo simulations as the important parameter for solute trapping has been modified for the local nonequilibrium diffusion case. An analytical expression has been developed for the velocity-dependent partition coefficient K which predicts …