자료유형 | 학위논문 |
---|---|
서명/저자사항 | Phase Field Simulations of the Coarsening of Complex Microstructures. |
개인저자 | Andrews, W. Beck. |
단체저자명 | University of Michigan. Materials Science and Engineering. |
발행사항 | [S.l.]: University of Michigan., 2019. |
발행사항 | Ann Arbor: ProQuest Dissertations & Theses, 2019. |
형태사항 | 182 p. |
기본자료 저록 | Dissertations Abstracts International 81-04B. Dissertation Abstract International |
ISBN | 9781687927453 |
학위논문주기 | Thesis (Ph.D.)--University of Michigan, 2019. |
일반주기 |
Source: Dissertations Abstracts International, Volume: 81-04, Section: B.
Advisor: Thornton, Katsuyo S. |
이용제한사항 | This item must not be sold to any third party vendors.This item must not be added to any third party search indexes. |
요약 | Coarsening is a fundamental phenomenon that occurs in a wide range of engineering materials, from polymer blends to cast aluminum alloys to functional nanostructured materials. The physics of coarsening is well understood. Differences in interfacial curvatures provide a driving force for mass transport, and the resulting evolution reduces the overall interfacial energy of the system as the average length scale of microstructural features increases. For simple particulate systems, such as those consisting of spherical precipitates at low volume fractions, analytical descriptions for the evolution are available and provide powerful tools for engineers to predict the microstructure for a given material and processing conditions. However, it is more difficult to predict the evolution of complex, well-connected structures like those present in dendritic solid-liquid systems and nanoporous metals. In these cases, simulations are necessary to develop fundamental understanding of coarsening and to gain the ability to predict microstructures that undergo coarsening. This dissertation consists of a series of simulation studies of coarsening of microstructures with complex morphologies. The simulation results and theories obtained here represent a fundamental contribution to the understanding of coarsening in complex microstructures.Coarsening with phases that have dissimilar mobilities is a condition typical of experimental solid-liquid systems. In a two-dimensional simulation, coarsening with dissimilar mobilities resulted in a morphological transition, as the initially complex, labyrinthine microstructure transforms into a system of high-mobility particles in a low-mobility matrix. In contrast, coarsening in three dimensions with dissimilar mobilities resulted in a stable bicontinuous structure after an initial transient stage. In this transient stage, we observed a theoretically predicted relationship between the coarsening rate constant and the variance of scaled mean curvature.Another important class of coarsening systems is those evolving by surface diffusion, including nanoporous metals. Intermediate volume fractions (between 36% and 50% minority phase) resulted in bicontinuous structures that coarsened self-similarly |
일반주제명 | Mathematics. Physics. Materials science. |
언어 | 영어 |
바로가기 | ![]() |