Computational and Modeling Challenges in Metals and Alloys for Extreme Environments: Extreme Environment Simulations from Nano- to Macro-scale
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS Structural Materials Division, TMS: Computational Materials Science and Engineering Committee, TMS: Integrated Computational Materials Engineering Committee
Program Organizers: Jean-Briac le Graverend, Texas A&M University; Jaafar El-Awady, Johns Hopkins University; Giacomo Po, University of Miami; Beñat Gurrutxaga-Lerma, University of Birmingham
Monday 8:30 AM
March 15, 2021
Room: RM 19
Location: TMS2021 Virtual
Session Chair: Jean-Briac le Graverend, Texas A&M University; Avinash Dongare, University of Connecticut
8:30 AM
Molecular Dynamics Modeling of the Influence of Magnesium Dopants on Grain Boundary Stabilization in Nanocrystalline Aluminum: Wenye Ye1; Leslie Mushongera1; 1University of Nevada, Reno
Nanocrystalline materials show exceptional mechanical properties relative to their coarse-grained counterparts. However, due a large volume fraction of grain boundaries in nanocrystalline materials, their properties are significantly influenced by this amorphous grain boundary phase. Consequently, they suffer from low stability and ductility in applications. The addition of dopants offers a singular approach to stabilize grain boundaries in nanocrystalline materials. To this end, integrated Monte Carlo and molecular dynamic simulations were done to elucidate the efficacy of magnesium dopants to stabilize the grain boundaries in nanocrystalline aluminum. The atomistic simulations show that magnesium atoms tend to segregate to grain boundaries which minimizes their energy. Nanocrystalline aluminum samples with different dopant contents were tested under tensile and compressive loads at room temperature. The results show that magnesium at grain boundaries reduce grain coarsening in addition to preventing failure in this region. Mechanical properties from these samples were also compared.
8:50 AM
Understanding Interface Properties Through Dislocation Dynamics Simulations in Metallic Nanolaminates: Aritra Chakraborty1; Miroslav Zecevic1; Abigail Hunter1; Xiang-Yang Liu1; Ricardo Lebensohn1; Laurent Capolungo1; 1Los Alamos National Laboratory
Metallic nanolaminates (MNL) are nanoscale systems with alternating layers of dissimilar materials, and serve as suitable model materials for characterizing failure modes common to all metals since their microstructure can be experimentally tailored to isolate distinct failure modes. The deformation of these structures is heavily dominated by the interface (grain or phase boundaries) behavior and, hence, understanding their role is critical in accurately predicting their structural failure. In this work, we will use continuum dislocation dynamics (DD) simulations to capture interface-dislocation interactions for different types of MNL, in an efficient fast Fourier transform (FFT) framework. Critical aspects of this work include studying the role of interface thickness, orientation, stress (de)localization and ease of slip transfer at the interface on overall material response. Successful characterization of such critical attributes will address significant questions about origin of failure in materials.
9:10 AM
A Thermo-mechanical Model of the Dynamics of Dislocation Fields in Transient Heterogeneous Temperature Fields: Manas Upadhyay1; 1LMS, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris
A thermodynamically rigorous model to simulate the dynamics of dislocations due to rapid/gradual solid-state heating-cooling or solid-state thermal cycling (SSTC), is proposed. The proposed model, called the Thermal Field Dislocation Mechanics (T-FDM) model, is an extended coupling of the FDM approach with the heat transfer problem. Its novelty lies in its unique ability to simulate: (i) dislocation generation/annihilation/motion under the action of mechanical and thermal (heat-flux/temperature) boundary conditions, and (ii) local temperature changes induced by moving dislocations with evolving densities. The model can be applied to study dislocation motion under the action of rapidly evolving boundary conditions such as those occurring during AM, quenching, etc. The range of applicability of the model, including dislocation interactions with evolving chemical species (precipitates, microsegregations, etc.) and up-scaling to the crystal plasticity level, will be discussed. Validity of model assumptions, e.g. local thermodynamic equilibrium, are discussed in the context of SSTC during AM.
9:30 AM
Multi-scale Simulations of Crystallographic Facet-orientation Dependent Corrosion Behavior in Metallic Alloys: Rongpei Shi1; Stephen Weitzner1; Tim Hsu1; Xiao Chen1; Tae Wook Heo1; Tuan Pham1; Christine Orme1; Morris Wang1; Brandon Wood1; 1Lawrence Livermore National Laboratory
The development of successful metal corrosion mitigation strategies is impeded by an incomplete mechanistic understanding of the connection between corrosion performance and microstructure; for instance, crystallographic facet dependent morphology and kinetics of pitting corrosion have not been fully addressed. Here, we present a meso-scale phase field model for pitting corrosion that takes into account interfacial electrochemical reactions, mass transport of electrolytes and morphological evolution of the corroding interface. The model is parameterized using facet-orientation dependent dissolution rates obtained by combining electron backscatter diffraction (EBSD) with atomic force microscopy (AFM). The model is then employed to quantify the individual and combine effect of different microstructure attributes and environment conditions on corrosion behaviors. The model can also be parameterized using facet-orientation dependent equilibrium dissolution potentials computed by density functional theory and then validated by EBSD and AFM measurements. Overall, the findings improve our understanding of the crystallographic controls of corrosion processes.
9:50 AM
The Role of Precipitates on the Microstructure-sensitive Creep Response of 347H Steel via Crystal Plasticity Simulations: Veerappan Prithivirajan1; Nathan Beets1; Aritra Chakraborty1; M Arul Kumar1; Ricardo Lebensohn1; Laurent Capolungo1; 1Los Alamos National Laboratory
The development of microstructure-sensitive models for the creep response of metals is necessary to accelerate the design and assessment of materials for high temperature applications. Creep is predominantly governed by diffusion- and dislocation- mediated processes for which the kinetics and kinematics are affected by the evolution of precipitates in the medium. Dislocation-precipitate interactions are complex processes dependent on multiple factors like size, shape, density, distribution, configuration, and type of precipitates, local stress state, and temperature. In this work, we propose a physics-based constitutive model accounting for the precipitate-dislocation interactions and capable of capturing the effects of multiple precipitates on the plastic response of steels. Among others we show that the newly proposed model can capture both correlated and uncorrelated precipitate bypass modes. An application is then pursued for the case of 347H steel.
10:10 AM
Lattice Orientation Effect on Intragranular Void Growth in Single- and Poly-crystalline Metals: Paul Christodoulou1; Sylvain Dancette2; Ricardo Lebensohn3; Eric Maire2; Irene Beyerlein1; 1University of California, Santa Barbara; 2Institut National des Sciences Appliquées de Lyon; 3Los Alamos National Laboratory
Void growth is an important deformation and damage mechanism in metals under extreme conditions and is dependent on the deformation of the material surrounding the voids. Recent developments in fast Fourier transform (FFT)-based modeling have allowed for faster and more thorough studies of grain-scale effects on void growth. The goal of this work is to understand the role of crystallography on void growth in FCC metals, and compare and cross-validate FFT-based and finite element (FE)-based models to predict crystallographic effects on void growth. To this end, voids in single crystals and polycrystals were simulated using a dilatational/crystal plasticity model implemented in an FFT-based solver (DVPFFT), as well as in its FE equivalent. This talk will discuss the developments made in both models, as well as the effect of crystallography on void growth, including the differences between single crystal and polycrystal materials.