Park, Min Soo (2009-12). Phase-field Models for Solidification and Solid/Liquid Interactions. Doctoral Dissertation. Thesis uri icon

abstract

  • The microstructure resulting from the solidification of alloys can greatly affect their properties, making the prediction of solidification phenomena under arbitrary conditions a very important tool in the field of computer-aided design of materials. Although considerable attention has been allocated to the understanding of this phenomenon in cases in which the solidification front advances freely into the liquid, the actual microstructure of solidification is strongly dependent of interfacial interactions. Over the past decade, the phase-field approach has been proved to be a quite effective tool for the simulation of solidification processes. In phase-field models, one or more phase fields ? (conserved and/or non-conserved) are introduced to describe the microstructure of a complex system. The behavior of a given microstructure over time is then simulated by solving evolution equations written in terms of the minimization of the free energy of the entire system, which is written as a functional of the field variables as well as their gradients and materials' constitutive equations. With the given free energy functional, the governing equations (phase-field equation, diffusion equation, heat equation and so on) are solved throughout the entire space domain without having to track each of the interfaces formed or abrupt changes in the topology of the microstructure. In this work I will present phase-field models for solidification processes, solid/liquid interactions as well as their applications.
  • The microstructure resulting from the solidification of alloys can greatly affect their properties,

    making the prediction of solidification phenomena under arbitrary conditions a very important

    tool in the field of computer-aided design of materials. Although considerable attention has been

    allocated to the understanding of this phenomenon in cases in which the solidification front advances

    freely into the liquid, the actual microstructure of solidification is strongly dependent of

    interfacial interactions. Over the past decade, the phase-field approach has been proved to be a

    quite effective tool for the simulation of solidification processes. In phase-field models, one or

    more phase fields ? (conserved and/or non-conserved) are introduced to describe the microstructure

    of a complex system. The behavior of a given microstructure over time is then simulated

    by solving evolution equations written in terms of the minimization of the free energy of the entire

    system, which is written as a functional of the field variables as well as their gradients and

    materials' constitutive equations. With the given free energy functional, the governing equations

    (phase-field equation, diffusion equation, heat equation and so on) are solved throughout the entire

    space domain without having to track each of the interfaces formed or abrupt changes in the

    topology of the microstructure. In this work I will present phase-field models for solidification

    processes, solid/liquid interactions as well as their applications.

publication date

  • December 2009