Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
Abnormal grain growth is characterized by the lack of a steady state grain size distribution. In extreme cases, the size distribution becomes transiently bimodal, with a few grains growing much larger than the average size. This is known as secondary grain growth. In polycrystalline thin films, the surface energy [gamma]s and film/substrate interfacial energy [gamma]s vary with grain orientation, providing an orientation-selective driving force that can lead to abnormal grain growth. We employ a mean field analysis that incorporates the effect of interface energy anisotropy to predict the evolution of the grain size/orientation distribution. While abnormal grain growth and texture evolution always result when interface energy anisotropy is present, whether secondary grain growth occurs will depend sensitively on the details of the orientation dependence of [gamma]i.
Mean Field Analysis of Orientation Selective Grain Growth Driven by Interface-energy Anisotropy
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
Abnormal grain growth is characterized by the lack of a steady state grain size distribution. In extreme cases, the size distribution becomes transiently bimodal, with a few grains growing much larger than the average size. This is known as secondary grain growth. In polycrystalline thin films, the surface energy [gamma]s and film/substrate interfacial energy [gamma]s vary with grain orientation, providing an orientation-selective driving force that can lead to abnormal grain growth. We employ a mean field analysis that incorporates the effect of interface energy anisotropy to predict the evolution of the grain size/orientation distribution. While abnormal grain growth and texture evolution always result when interface energy anisotropy is present, whether secondary grain growth occurs will depend sensitively on the details of the orientation dependence of [gamma]i.
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
Abnormal grain growth is characterized by the lack of a steady state grain size distribution. In extreme cases, the size distribution becomes transiently bimodal, with a few grains growing much larger than the average size. This is known as secondary grain growth. In polycrystalline thin films, the surface energy [gamma]s and film/substrate interfacial energy [gamma]s vary with grain orientation, providing an orientation-selective driving force that can lead to abnormal grain growth. We employ a mean field analysis that incorporates the effect of interface energy anisotropy to predict the evolution of the grain size/orientation distribution. While abnormal grain growth and texture evolution always result when interface energy anisotropy is present, whether secondary grain growth occurs will depend sensitively on the details of the orientation dependence of [gamma]i.
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 692
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 692
Book Description
Energy Research Abstracts
Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 486
Book Description
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 486
Book Description
Polycrystalline Thin Films
Author: Katayun Barmak
Publisher:
ISBN:
Category : Polycrystals
Languages : en
Pages : 806
Book Description
Publisher:
ISBN:
Category : Polycrystals
Languages : en
Pages : 806
Book Description
Polycrystalline Thin Films : Structure, Texture, Properties, and Applications
Author:
Publisher:
ISBN:
Category : Thin films
Languages : en
Pages : 818
Book Description
Publisher:
ISBN:
Category : Thin films
Languages : en
Pages : 818
Book Description
Government Reports Announcements & Index
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 584
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 584
Book Description
Physics Briefs
Author:
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 1256
Book Description
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 1256
Book Description
Metals Abstracts
Author:
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 628
Book Description
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 628
Book Description
Effect of Anisotropic Interfacial Energy on Grain Boundary Distributions During Grain Growth
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
Through simulations with the moving finite element program GRAIN3D, we have studied the effect of anisotropic grain boundary energy on the distribution of boundary types in a polycrystal during normal grain growth. An energy function similar to that hypothesized for magnesia was used, and the simulated grain boundary distributions were found to agree well with measured distributions. The simulated results suggest that initially random microstructures develop nearly steady state grain boundary distributions that have local maxima and minima corresponding to local minima and maxima, respectively, of the energy function. It is well known that the properties and area fractions of various grain boundary types in polycrystals have a dramatic effect on macroscopic materials properties. The goal of the present study is to examine the quantitative relation between grain boundary energies and the distribution of grain boundary types that result from grain growth. In keeping with the prior work, we parameterize the five-dimensional space of grain boundary types using three parameters to describe the lattice misorientation and two parameters to describe the orientation of the grain boundary plane. Of particular interest is the observation that at fixed misorientations, there is significant texture in the distribution of the grain boundary planes and planes with low surface energies appear more frequently. Here we use simulation to test the idea that the observed distributions arise because of the grain boundary energy anisotropy. In comparison to the experiments, the simulations are advantageous because they make it possible to monitor the time evolution of the distribution and to independently determine the influence of different grain boundary properties on the development of the distribution. A moving finite element program, GRAIN3D, has been developed with the capability to incorporate anisotropic grain boundary energy and mobility functions into grain growth simulations. We have modified the GRAIN3D code to simulate grain growth with anisotropic grain boundary energy and isotropic mobility.
Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
Through simulations with the moving finite element program GRAIN3D, we have studied the effect of anisotropic grain boundary energy on the distribution of boundary types in a polycrystal during normal grain growth. An energy function similar to that hypothesized for magnesia was used, and the simulated grain boundary distributions were found to agree well with measured distributions. The simulated results suggest that initially random microstructures develop nearly steady state grain boundary distributions that have local maxima and minima corresponding to local minima and maxima, respectively, of the energy function. It is well known that the properties and area fractions of various grain boundary types in polycrystals have a dramatic effect on macroscopic materials properties. The goal of the present study is to examine the quantitative relation between grain boundary energies and the distribution of grain boundary types that result from grain growth. In keeping with the prior work, we parameterize the five-dimensional space of grain boundary types using three parameters to describe the lattice misorientation and two parameters to describe the orientation of the grain boundary plane. Of particular interest is the observation that at fixed misorientations, there is significant texture in the distribution of the grain boundary planes and planes with low surface energies appear more frequently. Here we use simulation to test the idea that the observed distributions arise because of the grain boundary energy anisotropy. In comparison to the experiments, the simulations are advantageous because they make it possible to monitor the time evolution of the distribution and to independently determine the influence of different grain boundary properties on the development of the distribution. A moving finite element program, GRAIN3D, has been developed with the capability to incorporate anisotropic grain boundary energy and mobility functions into grain growth simulations. We have modified the GRAIN3D code to simulate grain growth with anisotropic grain boundary energy and isotropic mobility.
Publications of the National Institute of Standards and Technology ... Catalog
Author: National Institute of Standards and Technology (U.S.)
Publisher:
ISBN:
Category :
Languages : en
Pages : 1162
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 1162
Book Description