Microstructure Evolution in Sintering of Alumina-Zirconia Ceramics Simulated by a Modified Phase Field Method

2012 ◽  
Vol 715-716 ◽  
pp. 788-793
Author(s):  
Cheng Yang Wei ◽  
Sai Yi Li
Keyword(s):  
Grain Size ◽  
Phase Field ◽  
Volume Fraction ◽  
Field Method ◽  
Density Field ◽  
Phase Field Method ◽  
Green Density ◽  
Zirconia Ceramics ◽  
Final Density ◽  
Orientation Fields

The densification and grain growth during sintering of alumina-zirconia (Al2O3ZrO2) ceramics were simulated using a modified phase field method, which considered simultaneously a density field, a composition filed and orientation fields. The results indicate that the model can capture the main microstructure features in the different stages of sintering. A higher relative green density leads to a higher final density and a larger final grain size in the sintered ceramics. A higher volume fraction of the ZrO2 phase results in a lower relative density and a smaller final grain size.

Effects of External Stresses on the Martensitic Transformation in a 3D Polycrystalline Material Using the Phase Field Method

2013 ◽  
Vol 1535 ◽  
Author(s):  
Amer Malik ◽  
Gustav Amberg ◽  
John Ågren
Keyword(s):  
Martensitic Transformation ◽  
Phase Field ◽  
Volume Fraction ◽  
Polycrystalline Material ◽  
Landau Equation ◽  
Current Model ◽  
Field Method ◽  
Phase Field Method ◽  
Martensitic Microstructure ◽  
External Stresses

ABSTRACTIn the current study an elasto-plastic phase field (PF) model, based on the PF microelasticity theory proposed by A.G. Khachaturyan, is used to investigate the effects of external stresses on the evolution of martensitic microstructure in a Fe-0.3%C polycrystalline alloy. The current model is improved to include the effects of grain boundaries in a polycrystalline material. The evolution of plastic deformation is governed by using a time dependent Ginzburg-Landau equation, solving for the minimization of the shear strain energy. PF simulations are performed in 2D and 3D to study the effects of tension, compression and shear on the martensitic transformation. It has been found that external stresses cause an increase in the volume fraction of the martensitic phase if they add to the net effect of the transformation strains, and cause a decrease otherwise. It has been concluded that the stress distribution and the evolution of martensitic microstructure can be predicted with the current model in a polycrystalline material under applied stresses.

Effect of Grain Boundary Energy in Recrystallization Simulation by Phase Field Method

2020 ◽  
Vol 993 ◽  
pp. 953-958
Author(s):  
Yan Wu ◽  
Ren Chuang Yan ◽  
Er Wei Qin ◽  
Wei Dong Chen
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Grain Growth ◽  
Phase Field ◽  
Boundary Energy ◽  
Phase Field Model ◽  
Field Method ◽  
Phase Field Method ◽  
Grain Boundary Energy ◽  
Average Grain Size

In this paper, the effect of grain boundary energy in AZ31 Mg alloy with multi-order parameters phenomenological phase field model has been discussed during the progress of recrystallization. The average grain size of the recrystallization grain at a certain temperature and a certain restored energy but various grain boundary energies have been studied, and the simulated results show that the larger the grain boundary energy is, the larger the average grain size will be, and the speed of grain growth will increase with the increase of grain boundary energy. Additionally, temperature will also increase the grain growth rate.

Theoretical phase-field-method-based model of the γ phase dissolution of base metals in duplex stainless steels

2021 ◽  
Vol 26 ◽  
pp. 102150
Author(s):  
Dong-Cho Kim ◽  
Tomo Ogura ◽  
Ryosuke Hamada ◽  
Shotaro Yamashita ◽  
Kazuyoshi Saida
Keyword(s):  
Phase Field ◽  
Stainless Steels ◽  
Field Method ◽  
Duplex Stainless Steels ◽  
Phase Field Method ◽  
Base Metals ◽  
Phase Dissolution

scholarly journals Viscoelastic phase-field fracture using the framework of representative crack elements

2021 ◽  
Author(s):  
Bo Yin ◽  
Johannes Storm ◽  
Michael Kaliske
Keyword(s):  
Phase Field ◽  
Consistency Condition ◽  
Field Method ◽  
Anisotropic Elasticity ◽  
Phase Field Method ◽  
Internal Variables ◽  
Crack Model ◽  
Material Degradation ◽  
Discrete Crack ◽  
Deformation State

AbstractThe promising phase-field method has been intensively studied for crack approximation in brittle materials. The realistic representation of material degradation at a fully evolved crack is still one of the main challenges. Several energy split formulations have been postulated to describe the crack evolution physically. A recent approach based on the concept of representative crack elements (RCE) in Storm et al. (The concept of representative crack elements (RCE) for phase-field fracture: anisotropic elasticity and thermo-elasticity. Int J Numer Methods Eng 121:779–805, 2020) introduces a variational framework to derive the kinematically consistent material degradation. The realistic material degradation is further tested using the self-consistency condition, which is particularly compared to a discrete crack model. This work extends the brittle RCE phase-field modeling towards rate-dependent fracture evolution in a viscoelastic continuum. The novelty of this paper is taking internal variables due to viscoelasticity into account to determine the crack deformation state. Meanwhile, a transient extension from Storm et al. (The concept of representative crack elements (RCE) for phase-field fracture: anisotropic elasticity and thermo-elasticity. Int J Numer Methods Eng 121:779–805, 2020) is also considered. The model is derived thermodynamic-consistently and implemented into the FE framework. Several representative numerical examples are investigated, and consequently, the according findings and potential perspectives are discussed to close this paper.

Phase Field Model for Influence of Edge Dislocation on Precipitation

2011 ◽  
Vol 415-417 ◽  
pp. 1482-1485
Author(s):  
Chuang Gao Huang ◽  
Ying Jun Gao ◽  
Li Lin Huang ◽  
Jun Long Tian
Keyword(s):  
Edge Dislocation ◽  
Phase Field ◽  
Field Model ◽  
Phase Field Model ◽  
Field Method ◽  
Phase Field Method ◽  
Second Phase ◽  
Free Energy Function ◽  
Phase Nucleation ◽  
Good Agreement

The second phase nucleation and precipitation around the edge dislocation are studied using phase-field method. A new free energy function is established. The simulation results are in good agreement with that of theory of dislocation and theory of non-uniform nucleation.

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