Phase Transformations and Microstructural Evolution: Modeling and Simulation
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Phase Transformations Committee
Program Organizers: Yufeng Zheng, University of North Texas; Rongpei Shi, Harbin Institute of Technology; Stoichko Antonov, University of Science and Technology Beijing; Yipeng Gao, Jilin University; Rajarshi Banerjee, University of North Texas; Yongmei Jin, Michigan Technological University
Monday 8:00 AM
February 24, 2020
Room: 33B
Location: San Diego Convention Ctr
Session Chair: Rongpei Shi, Lawrence Livermore National Laboratory; Tae Wook Heo, Lawrence Livermore National Laboratory
8:00 AM
Interaction between Phase Transformations and
Dislocation Evolution: Phase Field Approaches
: Valery Levitas1; 1Iowa State University
Our recent results on the following basic problems of the phase field approach (PFA) and finite element simulations will be presented: 1. Multivariant martensitic phase transformations: nano- and microscale PFA, large strains, and lattice instability conditions. 2. PFA to dislocations at nano- and microscale, in particular, using contact problem. 3. Interaction between phase transformations and dislocations at nano- and microscale. 4. Application to plastic strain-induced phase transformations at high pressure and large shear: barrierless nucleation, drastic reduction of transformation pressure, local and coarse-grained thermodynamic equilibrium conditions, strain-controlled kinetics. 1. Levitas V.I. & Javanbakht M. JMPS, 2015, 82, 345-366. 2. Basak A. & Levitas V.I. JMPS, 2018, 113, 162-196. 3. Levitas V.I. IJP, 2018, 106, 164-185. 4. Babaei H. & Levitas V.I. IJP, 2018, 107, 223-245. 5. Levitas V.I., Esfahani S.E., & Ghamarian I. PRL, 2018, 121, 205701. 6. Basak A. & Levitas V.I., CMAME, 2019, 343, 368-406.
8:20 AM Cancelled
Phase-field Modeling of Precipitates in Multicomponent Alloys with Various Coherency States: Tianle Cheng1; Youhai Wen2; Jeffrey Hawk2; 1U.S. Department of Energy, National Energy Technology Laboratory / LRST; 2U.S. Department of Energy, National Energy Technology Laboratory
In precipitation strengthened alloys the coherency state at the interface between precipitate particles and the matrix affects the morphology/stability of precipitates, kinetics of precipitate coarsening and the mechanical performance of the alloy. Khachaturyan’s phase-field microelasticity approach provides a close-form solution for arbitrary coherent precipitates. Nevertheless, for arbitrary incoherent and semicoherent particles research effort is insufficient. Here a variational approach is developed, within the phase field framework, to model precipitation with various coherency states in a multicomponent alloy. Simulation results with respect to the equilibrium morphology and stress state of ellipsoidal precipitates with various coherency states are compared with literature results. Coarsening of precipitate particles with various coherency states is studied and discussed under the context of classical Ostwald ripening theory.
8:40 AM
Phase-Field Simulation of Grain Growth in Porous Materials: Miral Verma1; Rajdip Mukherjee1; 1Indian Institute of Technology Kanpur
In this work, a 3-dimensional phase-field model is proposed to simulate grain growth behavior in porous materials. Grain growth in porous materials depends upon the interaction between the grain boundary and pores. The interaction is affected by parameters such as pore size, shape and orientation. The surface energy anisotropy in pore can contribute towards polygonal shapes of pores which significantly changes the dragging force. In polycrystalline solid, pore shape is also dependent upon the surface mobility at pore-grain interface. In the present model, pores are not assumed to be stationary, so with sufficient surface mobility pore attachment and detachment and pore coalescence are also possible. Moreover, we are using active parameter tracking (APT) algorithm which allows us to simulate a large number of grains for better statistics without increasing further memory consumption or computational time.
9:00 AM
Phase-field Simulation of Microstructure Evolution during Solidification in Metal Additive Manufacturing: Jiwon Park1; Chang-Seok Oh1; 1Korea Institute of Materials Science
When a heat source passes over the build surface during additive manufacturing, the materials undergo rapid solidification that results unique microstructures and properties. Even in a single beam path with straight trajectory, solidification velocity and cooling rate vary with the relative position to the heat source which set different solidification conditions. In this research 3-dimensional microstructure evolution of FCC metal during rapid solidification in additive manufacturing is studied with phase-field modeling. Different solidification conditions extracted from thermal computation were taken to simulate microstructure evolution when the build metal is grown from pre-built layers in [100], [110], and [111] normal directions. The results are also compared with randomly nucleated microstructures.
9:20 AM
Multiphase Modeling of Artificial Aging in a Multicomponent Aluminum Alloy based on the Subcritical Growth Theory: Daniel Larouche1; Tohid Naseri1; Rémi Martinez2; Francis Breton3; Denis Massinon4; 1Laval University; 2Linamar Corporation; 3Rio Tinto; 4Montupet Laigneville
One of the major difficulties encountered in the modelling of aging in multicomponent alloys is to reproduce accurately the sequence of precipitation with the proper incubation time for each phase. This is especially difficult when many hardening phases are involved because of the number of parameters that have to be accounted for by the traditional nucleation and growth theories. The concept that nucleation is a two-step process including a subcritical growth regime can be used when the nucleation sites are activated right after the quench, which simplify the modelling to the growth rates of the precipitates. In this contribution, a growth and dissolution model including the effect of the interfacial mobility will be used to simulate the precipitation kinetics of Mg-Si precipitates in a ternary Al-Mg-Si alloy. It will be shown that the interfacial mobility of the different phases can explain the precipitation sequence in a very efficient and convincing way.
9:40 AM Break
10:00 AM
Mesoscale Models for Investigating Solid-state Phase Transformations in Metal Hydrides for Hydrogen Storage: Tae Wook Heo1; Xiaowang Zhou2; ShinYoung Kang1; Rongpei Shi1; Brandon Wood1; 1Lawrence Livermore National Laboratory; 2Sandia National Laboratories
Hydrogen storage mechanisms in metals are often operated by metal-to-hydride phase transformations. The phase transformations involve the complicated coupling of chemical/ physical processes, including surface/interfacial reaction, hydrogen diffusion, structural change, and large volume expansion. However, the lack of clear understanding of the associated processes and their impacts on storage reactions has hampered the acceleration of materials discovery and development for hydrogen storage. The mesoscale modeling framework can provide a unified platform for integrating necessary chemical and materials parameters, which enables systematic investigation of solid-state phase transformations. In this presentation, we discuss our recent efforts on the development of integrated mesoscale models that can directly incorporate parameters derived from predictive atomistic modeling approaches such as ab initio calculations and molecular dynamics simulations for solid-state hydrogen storage. Specifically, we demonstrate representative case studies for analyzing thermodynamic and kinetic impacts of phase transformations on (re/de)hydrogenation mechanisms, employing simple or complex metal hydrides.
10:20 AM
Atomistic modeling based on the Quasiparticle Approach of the Fcc-bcc Phase Transformations: Helena Zapolsky1; Mykola Lavrskyi1; Renaud Patte1; Olha Nakonechna1; Gilles Demange1; Frederic Danoix1; 1Gpm, Umr 6634
The kinetics of displacive phase transitions belongs to the most fundamental and fascinating fields of materials science. In particular, the microstructure of a steel is often developed by solid-state transformation from the high-temperature face-centered cubic (fcc) austenite to the low-temperature body-centered cubic (bcc) ferrite phases. The complexity of this transformation poses a challenging problem for modelling. In this paper, the atomistic quasiparticle approach has been used to study the kinetics path during fcc to bcc phase transformation. It is shown that initial bcc nucleus grows as a multivariant aggregate. The atomistic structure and mechanism of propagation of the interface between two variants and between fcc and bcc phases is under discussion.
10:40 AM
Lattice Boltzmann Phase-field Modelling of Solidification Process for the Ni-Nb Binary-alloy: Huang Xueqin1; 1Texas A&M University
Understanding of the microstructure evolution during solidification is very important to the understanding of Additive Manufacturing. Solidification is not only affected by thermal histories but fluid flow effects must be considered as well. In this work, the lattice Boltzmann model is coupled with a finite interface dissipation phase-field model to consider the influence of the fluid flow on solidification during AM of a Ni-Nb binary alloy. The buoyancy forces, resulting from the concentration and temperature gradients, induce particle velocity redistribution within the liquid phase. This affects the concentration of Nb at the interface, which lead to the microstructure change of the material. The lattice Boltzmann model is built to fulfill the mass and momentum conservation for binary-phase and the binary-phase Navier-Stokes equation can be derived from the LBM.
11:00 AM
Beyond Modified Mean Field: A Case for a Stochastic Grain Growth Model in the Short Time Limit: Chandra Pande1; Alex Moser1; 1Naval Research Laboratory
We discuss the basic mechanism of grain growth in three dimensions in metals and alloys. It is argued, a comprehensive grain growth model is best based on a stochastic process described by a Fokker Planck equation. We show that this concept is sufficient to determine almost all features of grain growth in general terms. The existence of the von Neumann law and its counterpart in three dimensions enables us to provide an explicit form of the Fokker Planck equation and thus determine many features of grain growth in great detail in the long time limit. Finally, we illustrate a path towards an analytical solution for three dimensional grain growth in the short time limit.