Grain Growth in the Solid Plus Liquid Two-Phase Field: Instability of Liquid Films at Migrating Grain Boundaries

1992 ◽  
Vol 94-96 ◽  
pp. 649-658
Author(s):  
S. Annavarapu ◽  
John Liu ◽  
R. Doherty
Keyword(s):  
Grain Boundaries ◽  
Grain Growth ◽  
Phase Field ◽  
Liquid Films ◽  
Two Phase

Microstructure of Polycrystalline MgO Penetrated by a Silicate Liquid

1996 ◽  
Vol 2 (3) ◽  
pp. 113-128 ◽  
Author(s):  
Sundar Ramamurthy ◽  
Michael P. Mallamaci ◽  
Catherine M. Zimmerman ◽  
C. Barry Carter ◽  
Peter R. Duncombe ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Grain Growth ◽  
Glassy Phase ◽  
Silicate Liquid ◽  
Two Phase ◽  
The Matrix ◽  
Devitrification Process ◽  
Phase Mixture

Dense, polycrystalline MgO was infiltrated with monticellite (CaMgSiO4) liquid to study the penetration of liquid along the grain boundaries of MgO. Grain growth was found to be restricted with increasing amounts of liquid. The inter-granular regions were generally found to be comprised of a two-phase mixture: crystalline monticellite and a glassy phase rich in the impurities present in the starting MgO material. MgO grains act as seeding agents for the crystallization of monticellite. The location and composition of the glassy phase with respect to the MgO grains emphasizes the role of intergranular liquid during the devitrification process in “snowplowing” impurities present in the matrix.

Concurrent grain growth and coarsening of two-phase microstructures; large scale phase-field study

2019 ◽  
Vol 159 ◽  
pp. 160-176 ◽  
Author(s):  
Ramanathan Perumal ◽  
Michael Selzer ◽  
Britta Nestler
Keyword(s):  
Field Study ◽  
Grain Growth ◽  
Phase Field ◽  
Large Scale ◽  
Two Phase

scholarly journals A physical model to express grain boundaries in grain growth simulation by phase-field method

2011 ◽  
Vol 60 (6) ◽  
pp. 068201
Author(s):  
Zhang Xian-Gang ◽  
Zong Ya-Ping ◽  
Wang Ming-Tao ◽  
Wu Yan
Keyword(s):  
Grain Boundaries ◽  
Physical Model ◽  
Grain Growth ◽  
Phase Field ◽  
Field Method ◽  
Phase Field Method ◽  
Growth Simulation

Comparative study of two phase-field models for grain growth

2009 ◽  
Vol 46 (2) ◽  
pp. 479-490 ◽  
Author(s):  
Nele Moelans ◽  
Frank Wendler ◽  
Britta Nestler
Keyword(s):  
Comparative Study ◽  
Grain Growth ◽  
Phase Field ◽  
Two Phase ◽  
Phase Field Models

Recovery and Recrystallization during Thermo-Mechanical Processing of Ti-6.5Al-1.5Zr-3.5Mo-0.3Si Alloy

2014 ◽  
Vol 783-786 ◽  
pp. 549-555
Author(s):  
Hui Qin Chen ◽  
Xiao Dong Zhao ◽  
Yue Sheng Chai ◽  
Chun Xiao Cao
Keyword(s):  
Grain Size ◽  
Kinetic Model ◽  
Dynamic Recrystallization ◽  
Grain Boundaries ◽  
Phase Field ◽  
Single Phase ◽  
Strain Rates ◽  
Mechanical Processing ◽  
Two Phase ◽  
Alpha Beta

In this investigation, microstructure evolution of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy during thermo-mechanical processing at temperatures in beta single-phase and alpha+beta two-phase fields was studied. Microstructure analyses indicate that: (1) in the beta single-phase field, dynamic recovery accompanied by geometric dynamic recrystallization at large strains takes place dominantly within elongated large prior beta grains with serrate grain boundaries during deformation at higher temperatures and lower strain rates; and discontinuous dynamic recrystallization occurs along elongated small prior beta grain boundaries during deformation at lower temperatures and higher strain rates. During discontinuous dynamic recrystallization, recrystallized grain size is a function of Zener–Hollomon parameter, and a modified Avrami recrystallized kinetic model was established. (2) In the alpha+beta two-phase field, the globularization process is a thermally activated process controlled by parameters of temperature and strain rate. A modified Avrami globularized kinetic model was established. The primary alpha grain size is a function of Z on a ln-ln scale.

A microstructure evolution model including dislocation plasticity

2000 ◽  
Vol 652 ◽  
Author(s):  
Fabrizio Cleri ◽  
Gregorio D'Agostino
Keyword(s):  
Grain Boundaries ◽  
Grain Growth ◽  
Microstructure Evolution ◽  
Evolution Model ◽  
Monte Carlo Algorithm ◽  
Triple Junctions ◽  
Two Phase ◽  
Grain Rotation ◽  
Dislocation Plasticity ◽  
Phase Liquid

ABSTRACTWe present a stochastic microstructure evolution model applicable to grain growth and its recent extensions, in particular relative to dislocation plasticity. The model is implemented by means of numerical simulations based on the velocity Monte Carlo algorithm. It describes the evolution of a two-dimensional microstructure by tracking the motion of triple junctions, i.e. the vertices where three grain boundaries meet. Grain boundaries can be modeled as straight or curved segments; the misorientation dependence of both grain-boundary energies and mobilities can be included, as well as grain rotation. We show simple examples of normal, abnormal and oriented grain growth. The model is already capable of dealing with a two-phase (liquid-solid) system, to simulate both grain growth and grain dissolution in the liquid. Finally, we report preliminary results of a recent extension of the model to include mechanical deformation from dislocation plasticity.

Phase Field Modelling of Microstructure Evolution in the HAZ of X80 Linepipe Steel

2012 ◽  
Author(s):  
Morteza Toloui ◽  
Matthias Militzer
Keyword(s):  
Grain Boundaries ◽  
Grain Growth ◽  
Microstructure Evolution ◽  
Phase Field ◽  
Phase Field Model ◽  
Carbon Diffusion ◽  
Austenite Decomposition ◽  
Austenite Grain ◽  
Austenite Grain Growth ◽  
Linepipe Steel

The heat affected zone (HAZ) during welding experiences a very steep temperature gradient which results in significant microstructure gradients. Thus, model approaches on the length scale of the microstructure, i.e. the so-called mesoscale, are useful to accurately simulate microstructure evolution in the HAZ. In this study, a phase field model (PFM) is employed to simulate austenite grain growth and austenite decomposition in the HAZ of an X80 linepipe steel microalloyed with Nb and Ti. The interfacial mobilities and nucleation conditions are obtained by benchmarking the PFM with experimental data from austenite grain growth and continuous cooling transformation tests. An effective grain boundary mobility is introduced for austenite grain growth to implicitly account for dissolution of NbC. Subsequently, austenite decomposition into polygonal ferrite and bainite is considered. For this purpose the PFM is coupled with a carbon diffusion model. Ferrite nuclei are introduced at austenite grain boundaries and suitable interfacial mobilities are selected to reproduce experimental ferrite formation kinetics. Bainite nucleation occurs for a sufficiently high undercooling at available interface sites (i.e. austenite grain boundaries and/or austenite-ferrite interfaces). For simplicity, the formation of carbide-free bainite is considered and a suitable anisotropy approach is proposed for the austenite-bainite interface mobility. The model is then used to predict austenite grain growth and phase transformation in the HAZ.

Overgrowth behavior at converging grain boundaries during competitive grain growth: A two-dimensional phase-field study

2020 ◽  
Vol 160 ◽  
pp. 120196
Author(s):  
Chunwen Guo ◽  
Tomohiro Takaki ◽  
Shinji Sakane ◽  
Munekazu Ohno ◽  
Yasushi Shibuta ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Field Study ◽  
Grain Growth ◽  
Phase Field ◽  
Two Dimensional

Investigation of grain boundaries for abnormal grain growth in polycrystalline SrTiO3

2010 ◽  
Vol 25 (2) ◽  
pp. 260-265 ◽  
Author(s):  
Shao-Ju Shih ◽  
Sergio Lozano-Perez ◽  
David J.H. Cockayne
Keyword(s):  
Grain Boundaries ◽  
Grain Growth ◽  
Energy Dispersive Spectrometry ◽  
Dominant Role ◽  
Morphological Type ◽  
Liquid Films ◽  
Model Material ◽  
Abnormal Grain Growth ◽  
Transmission Electron ◽  
Microstructural Behavior

Strontium titanate (SrTiO3) is widely used in electronic devices, and it is a model material for understanding the structural and dielectric properties of grain boundaries (GBs). In such materials, the GBs often play a dominant role in sintering and microstructural behavior. Abnormal grain growth (AGG) is a commonly observed phenomenon. Most studies explained that GBs contain continuous liquid films, and this liquid assists interface diffusion resulting in fast growth. However, few studies investigate the AGG behavior without any liquid. In this study, GB morphology and chemistry have been characterized by high-resolution transmission electron microscopy and x-ray energy-dispersive spectrometry, respectively. Different distributions of GB morphology have been observed in abnormal grains and matrix grains, and GB chemistry varies with different morphological type GBs. By correlating GB morphology and chemistry, a possible mechanism for AGG is proposed.

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