Multi Scale Modeling of Microstructure Deformation in Material Processing: On-Demand Oral: Multi Scale Modeling of Microstructure Deformation in Material Processing
Sponsored by: AIST Metallurgy—Processing, Products and Applications Technology Committee
Program Organizers: Lukasz Madej, AGH University of Science and Technology; Jaimie Tiley, Oak Ridge National Laboratory; Muszka Krzysztof, AGH University of Science and Technology; Danuta Szeliga, AGH University of Science and Technology
Friday 8:00 AM
October 22, 2021
Room: On-Demand Room 10
Location: MS&T On Demand
Session Chair: Krzysztof Muszka, AGH University
Hot Deformation Microstructure and Processing Map of Cast Ni-based Superalloy IN-100: Yusaku Hasebe1; Takehito Hagisawa2; Satoru Ohsaki2; Kazuya Kubo2; Cheng Yang2; Kenta Aoyagi2; Kenta Yamanaka2; Akihiko Chiba2; 1The Japan Steel Works LTD; 2Japan
In this study, the deformation behavior of the cast Ni-based superalloy IN-100 was investigated at elevated temperature, using the processing map based on the dynamic material model. Flow stress-strain curves were compensated considering the adiabatic heating during hot compression tests in various temperatures and strain rates. Power dissipation efficiency was calculated from the compensated true stress at each temperature and strain rate with the true strain of 0.3. At 1473K, power dissipation increased in the regions of both lower and higher strain rate. At lower strain rate, uniformly recrystallized grain which contains a few strain was observed. On the other hand, at higher strain rate, recrystallized region was observed partially around the local shear band. Change in the recrystallization behavior with varying deformation conditions and a relationship with the processing map will be discussed at the presentation.
Enabling Accurate Coarse-grained Atomistic Simulation of Defect Behavior in Random Alloys: Kevin Chu1; Adrian Diaz2; Youping Chen3; David McDowell1; 1Georgia Institute of Technology; 2Los Alamos National Laboratory; 3University of Florida
Concurrent multiscale modeling of random alloys faces a key complexity not encountered in purely atomistic or continuum models. Namely, the treatment of transition regions between length scales is of critical importance. Previously, force/energy-coupling based approaches have insufficiently addressed the stress fluctuations associated with solute misfit strains, especially close to the interface region. Here, we present a number of recent methodology advances in the Concurrent Atomistic-Continuum (CAC) implementation, including the leveraging of average EAM potentials, that allow for the dynamic simulation of large-scale multicomponent systems. The coupling artifacts present in other theories are eliminated in the CAC approach. We compute dislocation mobility trends across a composition range targeting 3XX austenitic stainless steels.
Numerical Studies of the Effect of Phase Stability on the Deformation Behavior of FeMnNiCoMo High Entropy Alloy: Kamil Cichocki1; Tomasz Koziel1; Grzegorz Cios1; Lukasz Madej1; Piotr Bala1; Krzysztof Muszka1; 1AGH University of Science and Technology
In the work, numerical modeling will be utilized to develop the stable face centered cubic structure of FeMnNiCoMo high entropy alloy. Approach based on Calphad and ab-initio methods will be presented. Group of model alloys with different Mo additions will be produced using arc melting. The effect of Mo addition of phase stability will be assessed using XRD and DSC studies. Finally, suspectibility of developed structures to plastic deformation will be experimentally and numerically studied based on the rolling process.
The Role of the Initial Digital Microstructure Generation Algorithm in the Cellular Automata Static Recrystallization Predictions: Mateusz Sitko1; Lukasz Madej1; 1AGH University of Science and Technology
Evaluation of the influence of the initial digital microstructure generation algorithm on the cellular automata static recrystallization model predictions is the work's primary goal. The initial digital microstructures were generated with unconstrained grain growth algorithms based on the Monte Carlo, Cellular Automata (CA), and Voronoi tessellation methods. The stored energy, which is a driving force for recrystallization, was distributed in homogenous and heterogeneous manners. Finally, based on such input data, the static recrystallization was simulated with the CA algorithm to identify the influence of initial grain boundaries morphology on the process kinetics.
Sensitivity Analysis, Identification and Validation of the Stochastic Model Describing Evolution of Microstructural Parameters during Hot Forming of Metallic Materials: Danuta Szeliga1; Natalia Czyżewska1; Konrad Klimczak1; Jan Kusiak1; Paweł Morkisz1; Piotr Oprocha1; Maciej Pietrzyk1; Paweł Przybyłowicz1; 1AGH University of Science and Technology
Construction metallic materials combine strength with formability. These features are obtained for heterogeneous microstructures with hard constituents dispersed in a soft matrix. On the other hand, sharp gradients of properties between phases cause local fracture. Advanced models are needed to design microstructures with smoother gradients of their features. Models based on stochastic variables meet this requirement. Our objective was to account for the random character of the recrystallization and to transfer this randomness to equations describing evolution of dislocations and grain size. The idea of the stochastic model is presented, as well as its identification and validation.
Cancelled
Temperature and Texture Dependent Constitutive Modeling of AZ31 Sheet Magnesium: Daniel Kenney1; Marcos Lugo1; Jared Darius1; 1Liberty University - School of Engineering
Magnesium alloys have a pivotal role as lightweight structural materials in the effort to reduce vehicle weight and increase fuel efficiency. With a lower melting temperature than most structural metals, and a Hexagonal Close-Packed atomic structure, the behavior of many wrought magnesium alloys is highly dependent on temperature and loading direction. This research investigates the behavior of AZ31 sheet under quasi-static monotonic tensile loading to understand the effects of temperature and orientation on failure mechanisms. Specimens are manufactured in the longitudinal and transverse directions to evaluate the effects of texture. A microstructural analysis characterizes the distribution of grain size, particles, and critical defects in each direction. Tests are run at room temperature, 100 °C, and 200 °C for both texture orientations. A constitutive damage model is implemented which incorporates the effects of microstructure and temperature to characterize material behavior and failure mechanisms.
Using Martensite Crystallography to Determine Transformation: Induced Deformation of Ferrite In Dual-phase Steels: Vibhor Atreya1; Cornelis Bos2; Maria Santofimia1; 1Delft University of Technology; 2Tata Steel R&D
During the production of ferrite-martensite dual-phase (DP) steels, the transformation of austenite into martensite involves a volumetric expansion and a shape change which the ferrite phase present in the microstructure accommodates through deformation. A description of ferrite deformation and the resulting local distribution of strain and stress is necessary to accurately model the subsequent mechanical behavior of DP steels. In this work, ferrite deformation is simulated by first obtaining the invariant plane strain associated with the martensitic phase transformation using the phenomenological theory of martensite crystallography. Subsequently, micromechanical modeling is used to simulate the transformation-induced ferrite deformation. The simulation results are compared to the deformation in the ferrite phase observed experimentally via electron backscatter diffraction measurements. The methodology presented in this work can be used to estimate the strain and stress resulting from martensitic transformation-induced deformation of the ferrite phase in DP steels.
Multi Scale Modeling with Microstructure Characteristics of Martensitic Steel for Rolling Contact Fatigue Life Prediction: Jinheung Park1; Kijung Lee1; Soonwoo Kwon2; Myoung-gyu Lee1; 1Seoul National University; 2Hyundai Motor Company
Bearing steels under rolling contact fatigue (RCF) typically have martensitic microstructure with high carbon contents to enhance resistance to cyclic contact stress in harsh environment. Under the RCF condition, the martensitic transformation of retained austenite and mechanical softening resulted from microstructural alterations occur at the subsurface of bearing steel. These microstructure effects combined with external loadings initiate cracks at subsurface and eventually leads to failure. The objective of this study is to predict the RCF life-span considering the microstructure characteristics of martensitic bearing steel. For this purpose, the hierarchical multiphase microstructure is virtually generated using Voronoi tessellation. Also, the crystal plasticity finite element model is extended by incorporating the microstructural alterations based on the dislocation-assisted carbon migration theory and the deformation-induced martensitic transformation. The crystal plasticity simulation coupled with the continuum damage mechanics enables to predict the RCF life-span.
Crystal Plasticity-based Forming Limit Prediction for Ultra-thin Bipolar Plate for Proton Exchange Membrane Fuel Cells: Minh Tien Tran1; Dae Ho Lee1; Huai Wang2; Ho Won Lee3; Dong-Kyu Kim1; 1University of Ulsan; 2Chinese Academy of Sciences; 3Korea Institute of Materials Science
In the present study, crystal plasticity finite element (CPFE) analysis in conjunction with the Marciniak-Kuczynski (M-K) approach was used to predict the forming limit diagram (FLD) of a 0.08 mm-thick bipolar plate designed for proton exchange membrane (PEM) fuel cells. The Nakazima formability test was employed to measure the FLD of the ultra-thin material. Uniaxial tensile test and electron backscatter diffraction (EBSD) measurement were conducted to characterize the mechanical behavior and to obtain the texture of the material. A hybrid representative volume element (RVE), governed by a rate-dependent crystal plasticity model, was developed and used in the forming limit analysis. The predicted FLD shows an excellent agreement with the experimental results. Furthermore, the effect of subsurface crystal orientations on the strain localization in ultra-thin bipolar plate is discussed in detail.
Crystal Plasticity Modeling of Twin Variant Selection in HCP Magnesium: Adwitiya Rao1; Anirban Patra1; 1IIT Bombay
A crystal plasticity finite element (CPFE) framework was developed for modeling deformation twinning in HCP magnesium. The anisotropic deformation of magnesium was captured by calibrating the model to single crystal experimental data for all possible deformation modes at room temperature. Furthermore, a novel energy-based criterion was proposed to model twin variant selection based on the dissipation of maximum energy due to twinning. The criterion was validated by comparing the simulated responses of single and polycrystals with available experimental data. Furthermore, a statistical analysis of twin variant selection was performed to predict the activation of certain non-Schmid twin variants, also observed in experiments. The simulated results were in qualitative agreement with the experimental data and could capture both Schmid and non-Schmid twin variants.
Study of Near Boundary Gradient Zones in an Aluminum Alloy Using Strain Gradient Crystal Plasticity and Experiments: Namit Pai1; Indradev Samajdar1; Anirban Patra1; 1Indian Institute of Technology Bombay
Geometrically necessary dislocations (GNDs) are created at grain boundaries for the accommodation of the lattice mismatch. Pileup of GNDs at grain boundaries results in a back stress, leading to the development of near boundary gradient zone (NBGZ) in metals. These regions generally experience higher deformation than the grain interiors. The current work proposes a dislocation density-based strain gradient crystal plasticity framework for simulating the NBGZs and their effect on the evolution of local and aggregate mechanical properties. The model uses electron back scattered diffraction (EBSD) patterns as input microstructures and then compares the evolution of misorientations and GND densities between the simulated and experimental microstructures. The combined modeling and experimental framework is used to study deformation in several grain clusters of an aluminum alloy during interrupted tensile testing and to study the effect of misorientation between neighboring grains on the development of NBGZs.