Integrated Computational Materials Engineering: Modeling and Simulation Applied to Metals Processing: Modeling and Simulation of Deformation and Associated Microstructure and Mechanical Properties
Sponsored by: MS&T Organization
Program Organizers: David Furrer, Pratt & Whitney
Thursday 8:00 AM
October 20, 2011
Room: C213
Location: Greater Columbus Convention Center
Session Chair: Fan Zhang, Penn State University
8:00 AM
An Integrated Framework of Experiments and Simulations for
Investigating Elastic-Plastic Deformation of Metallic Polycrystals: Jay Schuren1; Su Leen Wong2; Paul Dawson2; Matthew Miller2; 1AFRL; 2Cornell University
The traditional role for experiments in a simulation-based material design framework is one of validation or calibration. This talk describes a different, more coordinated approach, where high energy x-ray diffraction with in situ loading and crystal-based finite elements were combined to understand single crystal mechanical properties and the variation of inelastic deformation within polycrystalline AA7075-T6. We also use the integrated approach to define the uncertainties associated with measured and computed lattice strain pole figures.
8:20 AM
Phase Field Modeling of Grain Growth and Recrystallization in Elastoviscoplastically Deformed Polycrystals: Saswata Bhattacharya1; Tae Wook Heo1; Kunok Chang1; Ricardo Lebensohn2; Zi-Kui Liu1; Suveen Mathaudhu3; Long-Qing Chen1; 1Pennsylvania State University; 2Los Alamos National Laboratory; 3Army Research Laboratory
An efficient phase field - crystal plasticity model is developed to study elastoviscoplastic deformation in polycrystals. Both elastic and plastic anisotropy and inhomogeneity are taken into consideration in our model. The governing equations are solved using an efficient Fourier spectral method. We calculate the local fields (strain rate, stress, accumulated plastic strain) when a polycrystalline system is subjected to elastoviscoplastic deformation. The stored energy is calculated based on the local fields. When the deformed polycrystal is subjected to annealing, strain free grains nucleate and grow and the grains reorient to minimize the stored and grain boundary energies. Grain boundary migration is described using a modified Allen-Cahn equation which takes into account the driving forces due to curvature and minimization of elastic and plastic strain energy. We present the results from two- and three-dimensional simulations of grain growth and recrystallization in elastoviscoplastically deformed FCC and HCP polycrystalline systems.
8:40 AM
Elastic Strain Energy Effects on Grain Boundary Segregation and Solute Drag in Grain Boundary Motion: A Phase-Field Study: Tae Wook Heo1; Saswata Bhattacharyya1; Long-Qing Chen1; 1The Pennsylvania State University
We study strain-induced grain boundary (GB) segregation and solute drag in GB migration using the phase-field method. The elastic strain energy of a solid solution due to atomic size mismatch between solutes and host atoms in a polycrystal is formulated. The coherency strain energy from compositional inhomogeneity is calculated using the Khachaturyan’s theory. We first simulate GB segregation on a static flat GB and compare the results with the analytic solution for validation. GB is then allowed to move to perform the parametric studies of solute drag with strain energy contribution. The theoretical analysis shows that the enhancement of the drag force with increasing atomic size mismatch stems from both the increase of grain boundary segregation and misfit strain relaxation itself near the grain boundary. We identify the optimum condition for the strongest drag force under a given driving force for grain boundary motion.
9:00 AM
Three Dimensional Elasto-Plastic Phase Field Simulations of Martensitic Transformation in Fe-C Polycrystalline Alloy: Amer Malik1; Gustav Amberg1; 1KTH
The Phase Field (PF) Microelasticity model proposed by A.G. Khachaturyan is used to perform three-dimensional simulations of Martensitic Transformation (MT) in polycrystal using finite element method (FEM). The effect of plastic accommodation is investigated by using a time dependent Ginzburg-Landau (TDGL) equation for evolution of plastic deformation. In this paper, PF simulations are performed in 2D and 3D for different initial and boundary conditions to simulate FCC-to-BCT martensitic transformation in Fe-0.3%C polycrystalline alloy. The simulation results depict that the introduction of plastic accommodation reduces the stress intensity in the parent phase and hence causes an increase in volume fraction of the martensitic phase. Simulation results also show that martensitic transformation nucleates at the grain boundaries and grow into the parent phase. It has been concluded that stress distribution and the evolution of microstructure can be predicted in a polycrystalline alloy with the current model.
9:20 AM
Phase-Field Simulation of Elastic Properties of Polycrystalline Magnesium: Guang Sheng1; Saswata Bhattacharya1; Hui Zhang1; Kunok Chang1; Suveen Mathaudhu2; Zi-Kui Liu1; Long-Qing Chen1; 1The Pennsylvania State University; 2U.S. Army Research Laboratory
We report an efficient phase-field approach to computing the effective elastic properties of magnesium polycrystals with arbitrary elastic inhomogeneity and anisotropy. The dependence of elastic stiffness tensor on grain orientation is taken into account, and the elastic equilibrium equation is solved using a spectral iterative perturbation method. With the single elastic properties from first-principles calculations as input, the obtained temperature dependence bulk modulus, shear modulus and Young’s modulus of magnesium polycrystalline agree well with available experimental data. The texture dependence on effective elastic properties will be discussed by integrating the typical texture components in magnesium rolling sheets.
9:40 AM Break
10:00 AM
Precipitation Simulation of Multi-Component Nickel and Aluminum Alloys under the ICME Framework: Weisheng Cao1; Fan Zhang1; Shuanglin Chen1; Chuan Zhang1; Y. Austin Chang2; 1CompuTherm LLC; 2University of Wisconsin - Madison
In this presentation, I will demonstrate the success of using ICME approach to simulate the evolution of the microstructure and the correlated mechanical properties for multi-component alloys during precipitation process. The necessary mobility data and thermodynamic properties are provided by the Calphad method. The modeling of microstructural evolution is based on the KWN approach, which considers the concurrent nucleation, growth and coarsening. The obtained microstructure information will serve as key inputs for the estimation of mechanical properties. By following this approach, an integrated computational tool is under development. Preliminary results will be presented for the precipitation simulation of a number of multi-component Nickel-based superalloys, and the prediction of age hardening behavior of a series of AA6xxx aluminum alloys, as well as the predication of the final microstructure and mechanical properties of Al casting alloys by coupling with ProCAST. The advantage and limitation of this approach will also be discussed.
10:20 AM
Self-Similar Evolution of a Precipitate in Homogeneous Elastic Media: Shuwang Li1; Amlan Barua1; Xiaofan Li1; John Lowengrub2; 1Illinois Institute of Technology; 2UC-Irvine
We present a linear theory describing self-similar growth of a precipitate in an elastic media. The existence and stability of self-similar crystals growing in a diffusion field were demonstrated in our previous work. Here, we extend the theory and simulations into solid-state phase transformations where elasticity plays an important role on the shape evolution of precipitates in a matrix phase. We first revisit the linear analysis and investigate the relation between the diffusion and elastic fields. For given applied shear, dilatation and misfit conditions, we demonstrate that there exist critical scaling of flux and elasticity at which self-similar evolution occurs. These results show that the classic Mullins-Sekerka instability that leads the precipitate evolving into dendritic shapes can be controlled. Specifically, the size of the precipitate grows like R ~ t^{1/3}. Preliminary nonlinear simulations show that self-similar shapes are stable with respect to perturbations of diffusion flux and precipitate shape.
10:40 AM
An Integrated Heat Treatment Model for Cast Aluminum Alloys: Chang-Kai Wu1; Makhlouf Makhlouf1; 1Worcester Polytechnic Institute
A mathematical model is being developed to allow predicting the response of aluminum alloy castings to heat treatment. The model takes into account all three stages of the typical T6 heat treatment; i.e., the solutionizing, quenching, and aging stages, and when complete, it will allow predicting the local hardness and mechanical properties within a cast component, as well as the magnitude of residual stresses and dimensional changes that may be induced by the heat treatment. In this publication, we report on the measurements that produce the database and the heat transfer coefficients that are required by the model. In its current stage of development the model can accurately predict hardness; therefore in this publication we only compare measured values of hardness to their model-predicted counterparts. However, we also present details of ongoing work that will eventually extend the model to allow predicting mechanical properties, residual stresses, and overall dimensional changes.
11:00 AM
Microstructures Design in Three-Component Alloys: Vasily Lutsyk1; Edward Nasrulin2; 1Institute of Physical Materials Science; 2Buryat State University
Alternative principles of the phase diagrams (PD) design have been offered (Lutsyk V.I. et al. Z. Naturforsch. A, 2008, 63a, 513; Crystallography Reports, 2009, 54, 1300 & 2011, 56; J. Thermal Analysis & Calorimetry, 2010, 101, 25): 1) the assembly of whole diagram starts with the space scheme of monovariant reactions; 2) contours of the surfaces with the unruled nature are to be closed and data of thermodynamical calculations are used on this stage; 3) surfaces should be approximated as the minimal ones; 4) all geometrical elements are designated, and these “names” contain their meaning; 5) after the computer assembling the PD space model changes into a useful tool to solve different fundamental and applied tasks. At any step of crystallization path it is possible to have the material balances, where the crystals of different origin will be differentiated. Concurrency of crystals with different dispersity produces different microstructures.
11:20 AM
Parts Heat Treatment Temperature Monitoring System Using C# Language: Tian Weiwei1; cao wenzhong2; 1 Environmental & Chemical Engineering College of Nanchang University; 2Environmental & Chemical Engineering College of Nanchang University
The paper provides an automatic solution for monitoring and managing the heat treatment of drill pipes. It improves the efficiency and accuracy of heat treatment and ensures the quality of drill pipes. It is hence much practical. The software is implemented by using C#+SQL Server 2000 and Visual Studio 2008 as the main development tool.It applies ADO.NET to get access to database. The software realizes the real-time monitoring function in the process of heat treatment, faulty alarm,data tendency analysis,printing recording and inquiring the history data of drill pipes. The software has a unified and friendly operating interface and provides multiple interfaces for users so that it is easy to use.