Computational Thermodynamics and Kinetics: Poster Session
Sponsored by: TMS Functional Materials Division, TMS Materials Processing and Manufacturing Division, TMS Structural Materials Division, TMS: Chemistry and Physics of Materials Committee
Program Organizers: Vahid Attari, Texas A&M University; Sara Kadkhodaei, University of Illinois Chicago; Eva Zarkadoula, Oak Ridge National Laboratory; Damien Tourret, IMDEA Materials Institute; James Morris, Ames Laboratory

Tuesday 5:30 PM
March 1, 2022
Room: Exhibit Hall C
Location: Anaheim Convention Center

Session Chair: Vahid Attari, Texas A&M University; Prashant Singh, Ames Laboratory/US Department of Energy; Mira Tadarova, Max-Planck-Institut für Eisenforschung GmbH

O-1: A CALPHAD Approach to Alloy Design for Printability and Performance When Additively Manufactured: Soumya Mohan1; Branden Kappes2; Akansha Singh3; Ben Rafferty4; Jeremy Iten4; Sridhar Seetharaman5; Aaron Stebner1; 1Georgia Institute of Technology; 2KMMD, LLC; 3Shell Technology Center; 4Elementum 3D; 5Arizona State University
    CALPHAD-based Integrated Computational Materials Engineering (ICME) approaches to design alloys for additive manufacturing (AM) are challenged by gaps between the quasi-equilibrium assumptions of CALPHAD and often non-equilibrium realities of AM, such as rapid cooling and complex thermal histories. Developing a computational framework that reliably predicts “easy-to-print” alloys with targeted properties is crucial to accelerating alloy design and reducing experimental trial-and-error. We present an approach that integrates CALPHAD calculations of liquidus temperatures, non-equilibrium weld solidification simulations based on Scheil-Gulliver models, hot cracking susceptibility, solidification driving forces of likely phases, and yield strength predictions. This approach combines computational modeling with metallurgical domain expertise and metaheuristic optimization methodologies and are demonstrated on austenitic stainless steels and 5000 series aluminum alloys for laser powder bed fusion.

O-3: A Study on the CFD Simulation of Microbubbles Generation and Movement during the Mineral Flotation Process: Guihong Han1; Hao Wu1; Yanfang Huang1; Shengpeng Su1; Bingbing Liu1; 1Zhengzhou University
    Generation, movement and distributions of microbubbles in complex solution environment are universal phenomenon in the chemical engineering, minerals processing, extractive metallurgy, and wastewater treatment. During the mineral flotation process, the separation efficiency design largely depends on the characteristics of microbubbles in the composite force fields. In current work, the effect of water velocity and airflow velocity on the generation, movement and distribution of microbubbles were investigated by the Computational Fluid Dynamics (CFD) simulation. Steady and transient states of microbubbles generated via a microbubble generator are calculated using the standard k-ε turbulence model and the Eulerian-Eulerian multiphase flow model. The experimental data presented in the paper are used to validate the CFD model. Moreover, the effect of diverging angle and ratio of throat length to throat diameter on the microbubble size were also evaluated. CFD simulation of microbubbles generation and movement is an important means to explore the flotation mechanism.

O-4: Analysis of the Kinetic Process of Carbothermal Reduction of ZnFe2O4: Ning Mao1; Chengbo Wu1; yang Wang1; Zhihui Guo1; 1Chongqing University
    This paper analyzes the kinetics of the reduction process of ZnFe2O4. Aiming at the ZnFe2O4 in the electric furnace dust, by analyzing the change of the reduction degree of ZnFe2O4 carbothermal reduction with time and temperature, the possible restrictive links such as carbon gasification, interface chemical reaction, internal diffusion and external diffusion are comprehensively investigated. The limiting link and kinetic equation of ZnFe2O4 reduction were studied.

O-5: Atomistic Scale Studies of Shape Memory Ceramic Bismuth Ferrite (BiFeO3): Henan Zhou1; Doyl Dickel1; Michae Baskes2; Sungkwang Mun1; Mohsen Zaeem3; 1Center for Advanced Vehicular Systems; 2University of North Texas; 3Colorado School of Mines
    An interatomic potential for shape memory ceramic, bulk bismuth ferrite (BiFeO3), has been developed based on the second nearest-neighbor modified embedded-atom method (2NNMEAM) and the charge equilibration method (Qeq). The potential is used to describe a range of physical properties, such as lattice constant, cohesive energy, elastic constants, and charge representation of BiFeO3 in several different phases (R3c, P4mm, and Pm3m). The calculations show good agreement with density functional theory (DFT), Bader charge analysis, and experimental data. The developed BiFeO3 potential is applied to the shape memory behavior and phase transformation of BiFeO3.

O-6: Dehydrating MgO Surface to Improve Mg Corrosion Resistance: Insights From Atomistic Simulations: Chi Zhang1; Xin Li1; Junsheng Wang1; 1Beijing Institute of Technology
    Mg corrode rapidly due to the hydrophilic wetting MgO surface. Here we present the effects of NaCl solution concentration, temperature, and lattice constant on the wettability of MgO surfaces using atomistic simulations. It was found that the configuration of water molecules has a big impact on the dehydrating of MgO surface, which can be used to transform MgO surface from hydrophilic to hydrophobic.

O-7: Identification of the Eutectic Composition in the Multicomponent Systems with the High Throughput CALPHAD Approach: Jize Zhang1; Rui Wang1; Yu Zhong1; 1Worcester Polytechnic Institute
    Eutectic compositions in metallic systems can be instrumental in various applications, such as metallic glasses or eutectic alloys. Although it is relatively easy to determine eutectic temperatures in binary or ternary systems, it requires lots of work when more components are present. In this work, a high throughput numerical method based on the CALPHAD(Computer Coupling of Phase Diagrams and Thermochemistry) approach and the TC-Python Kitware established to determine eutectic compositions of the Al-Mg-Cu-Zn quaternary system as a case study. Firstly, the liquidus and solidus temperatures of each auto-generated composition are determined from TC-Python. Secondly, the eutectic compositions were further ruled out based on the two facts that the liquidus temperature of the candidate composition should be the local minimum among the adjacent compositions, and the temperature difference between the liquidus and the liquidus solidus temperatures should be close to zero. Finally, the candidate compositions were comprehensively compared with existing literature.

O-8: First-principles Calculations and Thermodynamics Modeling of the Ca-Zn System: Chuliang Fu1; Bicheng Zhou1; 1University of Virginia
     Thermodynamic modeling of the Ca-Zn system is performed by means of the CALPHAD approach combined with available experimental data in the literature and first-principles calculations in the present work. The finite temperature thermodynamic properties of the most compounds in the CaZn system are predicted with the quasi-harmonic phonon calculations and the Debye model based on the results from the first-principles calculation. In addition, first-principles calculations were performed on bcc, fcc and hcp special quasirandom structures (SQS) to predict the enthalpy of mixing in the solidsolution phases. The associate solution model is used to describe liquid phase to capture the short-range ordering behavior in liquid.

O-9: Formation of Grain Boundaries during Polycrystalline Solidification of hcp Alloys: Ahmed Kaci Boukellal1; Maral Sarebanzadeh2; Alberto Orozco-Caballero3; Federico Sket1; Javier Llorca2; Damien Tourret1; 1IMDEA Materials Institute, Madrid (Spain); 2IMDEA Materials Institute and Department of Materials Science, Polytechnic University of Madrid/Universidad Politécnica de Madrid, E.T.S. de Ingenieros de Caminos, Madrid (Spain); 3Department of Mechanical Engineering, Chemistry and Industrial Design, Polytechnic University of Madrid/Universidad Politécnica de Madrid, E.T.S. Ingeniería y Diseño Industrial, Madrid (Spain)
     Novel lightweight alloys with good mechanical properties, like Magnesium (Mg) based alloys, reduce considerably the energy consumption in transport applications. Most Mg alloys are produced through solidification processes. Grains structures that emerge during this stage affect the mechanical properties and lifetime of the cast component. Therefore, understanding the grains formation during polycrystalline solidification of hcp materials (e.g. Mg) is key to develop novel alloys and to optimize these processes. We explore the effect on microstructure selection of the: (1) choice of anisotropy function for solid-liquid interface properties, (2) crystalline orientation of competing grains, (3) processing conditions. We focus on the competitive grain growth dynamics, and the selection of dendritic patterns and grain boundaries. We compare our computational results to experimental observations performed on directionally solidified thin samples of Mg alloys.This study brings a deeper insight into the mechanism of selection during polycrystalline columnar solidification in hcp systems.

O-10: Grain Precipitation and Growth Model of TiN Inclusions in 22MnB5 Steel: Haohao Zhang1; Jialu Wu1; Wei Guo1; Songyuan Ai1; Mujun Long1; Huamei Duan1; Dengfu Chen1; 1Chongqing University
    The accurate control of TiN particle size plays an important role in the control of slab quality. A model which can accurately predict the size of TiN particles in slab is established by thermodynamic calculation and experimental investigation. The precipitation behavior and mechanism of TiN particles in 22MnB5 steel are clarified. The result shows that TiN particles begin to precipitate in the solid-liquid two-phase region during solidification, and the initial precipitation temperature is 1776k (solid fraction is 0.3553).With the increase of cooling rate, the particle size of TiN inclusions decreases greatly. The increase of Ti and N content will lead to the advance of precipitation time and increase of particle size. Therefore, the size of TiN particles can be controlled in an appropriate range by reasonably controlling the cooling rate of continuous casting and the content of Ti and N in steel.

O-11: Numerical Modelling of Powder Spreading, Meltpool Dynamics, and Grain Structure Evolution during Additive Manufacturing: Daniel Dreelan1; Gowthaman Parivendhan1; Philip Cardiff1; Alojz Ivankovic1; David Browne1; 1University College Dublin
    The powder bed fusion (PBF) process, an additive manufacturing technique, uses a laser/electron beam to selectively melt and fuse metal powder in a layer-wise manner to fabricate products. The complexities that arise during fabrication can be modeled using numerical methods, aiding experiments to provide a better understanding of the process. Here we use discrete element method modelling to simulate the powder particles’ arrangement during spreading, and computational fluid dynamics simulations to predict the subsequent melt pool formation and dynamics. The thermal conditions during solidification are critical to the formation of microstructure. A cellular automata model is used to simulate grain structure evolution using the predicted thermal field: solidification kinetics are related to local liquid undercooling. The numerical meltpool and the microstructure prediction for different process parameters have good agreement with experimental results. The outcome will be used to develop a process-structure-property relationship, focusing on improving the capabilities of PBF processes.

O-12: Quantitative Electrochemical Phase-field Modeling for Corrosion of Engine Materials at High Temperature: Xueyang Wu1; Michael Tonks1; 1University Of Florida
    The stainless steel (SS) valve materials in an internal combustion engine (ICE) environment can undergo microstructural evolution that sensitizes the material to corrosion and fatigue. The industry currently employs a conservative material selection approach that usually results in over-design and increased cost. The goal of this work is to develop a mesoscale electrochemical phase-field simulation tool that investigates the mechanism of SS corrosion in an ICE, and determines the microstructural sensitive corrosion rate. Different oxide species observed in the experimental characterizations are included. With different ions diffusing, charge neutrality and coupled current conditions are assumed to simulate how the electric potential affects corrosion. In 2-D simulations, the influences of microstructure such as grain boundary and void are considered. The phase-field model is implemented using the Multiphysics Object Oriented Simulation Environment (MOOSE), an open-source finite-element framework. The predicted corrosion rate has been verified against analytical models and validated against experimental data.

O-13: Revisit the VEC Criterion with High-throughput Ab Initio Calculations: A Case Study with Al-Co-Cr-Fe-Ni System: Songge Yang1; Yu Zhong1; 1Worcester Polytechnic Institute
    Valence electron concentration (VEC) was treated as a useful parameter to predict the stability of solid solution phases. However, the available experimental data to support this criterion is far from enough. In the current study, the high-throughput ab initio modeling is applied to investigate the relative stability of FCC and BCC Al-Co-Cr-Fe-Ni HEA single crystals by using the special quasi-random structure (SQS) approach. The predictions will start with pure elements of the Al-Co-Cr-Fe-Ni system and will be continued with binaries, ternaries, quaternary, and quinary compositions. More than 300 compositions were simulated. After that, the reliability of the VEC criterion will be testified start from pure elements to the quinary alloys.

O-14: Simulation of Steam Film Motion Process on the Surface of Zirconium Alloy Rod: Juyi Pu1; Xiao Ping Liang1; Shuang Liang1; Bai Feng Luan1; 1Chongqing University
    The motion of steam film on the surface of zirconium alloy rod in cooling water was studied by numerical simulation. The influences of the initial temperature of the zirconium alloy rod and the temperature of the cooling water on the motion process of the steam film and the velocity of the quenching front were analyzed. The steam film motion process on the surface of the zirconium alloy rod was analyzed and compared when the cooling water was 100℃ and the initial temperature of the zirconium alloy rod was 650℃, 800℃ and 880℃ respectively. The results show that with the increase of initial temperature, the speed of quenching front is faster. At temperatures of 100℃, a large number of bubbles form in the cooling water surrounding the rods, but at the lower temperatures, the number of bubbles decreases.

O-15: Structural Ordering and Dynamics of Cu-Ag Chemically Heterogeneous Solid-liquid Interface: Boqiang Wu1; 1School of materials science and engineer,Shanghai Jiao Tong University
    The structural ordering and dynamics of chemically heterogeneous solid-liquid interfaces (SLI) between the Cu-Ag eutectic melts and pure Cu (Ag) are studied by performing molecular dynamics simulations. The microstructure of the liquid phase adjacent to the solid matrix tends to be ordered, and the properties of SLI are anisotropic due to the orientation dependence of the SLI width (ω110 > ω100 > ω111). In-plane and out-plane order of the interfacial atomic layers should be considered comprehensively to learn the orientation dependence of SLI, rather than only the atomic number density distribution perpendicular to the interface. The region of SLI is considered as a mixture of liquid and solid atoms according to the Lindemann criterion. Besides, the dynamics of SLI not only depend on the orientation, but also related to the type of matrix. Our findings are believed to be helpful for understanding the SLI and crystal growth of Cu-Ag alloys.

O-16: Ternary Phase Diagram Determination for Understanding and Modeling of the TCP Phase Formation in Ni-based Superalloys: Chuangye Wang1; Hui Sun2; ShunLi Shang2; Zi-Kui Liu2; Ji-Cheng Zhao1; 1University of Maryland; 2Pennsylvania State University
    Ni-based superalloys are used to make the most critical components of jet engines and power generation gas turbines. Formation of the topologically close-packed (TCP) phases (Sigma, Mu, Ρ and Laves) is detrimental to the properties of superalloys when highly alloyed with refractory elements. Accurate predictions of TCP phase formation will significantly accelerate alloy and process development by reduction of both the long-term exposure experiments and the number of experimental iterations. Diffusion multiples are utilized to collect large amount of tie-line data for the ternary systems within the Cr-Fe-Mo-Nb-Ni system. The large amount of data from our experiments and from the literature are fed to high-throughput assessments using the ESPEI open-source package to obtain more reliable thermodynamic parameters for reliable predictions for TCP phase formation.

O-17: The Electronic Structures of Anosovite with Different Components: Pan Deng1; Liang Li1; Dachun Liu1; Xiumin Chen1; 1Kunming University of Science and Technology
    With the decrease of rutile resources in the world, the exploitation and utilization of low-grade titanium resources has gradually become the focus of the world titanium smelting industry. However, the composition of low-grade titanium resources is complex and changeable with the substitution of Ti by Mg and Fe. The differences of complex oxide will generate in electronic structure, crystal structure parameters and stability, which eventually leads to changes in chlorination properties. To our knowledge, the study of electronic structure of anosovite with different components has not been systematically reported. Based on the present situation, the First-principles program package Vienna Ab Initio Simulation Package (VASP) was used to calculate the electronic structure differences of Ti3O5, MgTi2O5, FeTi2O5 and MgTi4FeO10, which has a great influence on the adsorption of chloride ions in the carbochlorination process of M3O5(M:Ti,Mg,Fe).

O-18: Thermal Vibration Effects on Physical Gas Adsorption: Computational and Experimental Study: Ziyi Wang1; Claire Saunders1; Camille Bernal1; Cullen Quine1; Brent Fultz1; 1Caltech
    Van der Waals (vdW) interactions are the fundamental interactions in gas physisorption that do not explicitly depend on temperature. However, our new experimental studies show that physisorption energy has temperature dependence. One possible source of this temperature dependence is the lattice thermal vibrations. This study compares thermal fluctuations at temperatures from 0 K to 1500 K on the krypton adsorption process on graphite. Thermal vibrations at each temperature are simulated with the stochastic Temperature Dependent Effective Potential (TDEP) method. We perform DFT calculations for each thermally displaced configuration with Tkatchenko-Scheffler (TS) and the Many-body dispersion (MBD) corrections to calculate absorption energy. Preliminary results comparing the accuracy of TS and MBD will be presented along with calculated values for adsorption energy of each geometry and temperature. Implications for experimental work will be discussed.

O-19: Thermodynamic Assessment of the SiO2-Y2O3 System: Wenke Zhi1; Fei Wang1; Xiaoyi Chen1; Bin Yang1; Yongnian Dai1; Yang Tian1; 1Kunming University of Science and Technology
    The phase relations and homogeneity ranges are helpful to optimize the functional performance of SiC/SiC ceramic matrix composites. Based on the calculated phase diagram (CALPHAD) method, the SiO2-Y2O3 system has been thermodynamically assessed based on experimental data available. The liquid phase is described by the modified quasichemical model and all solid phases are treated as stoichiometric compounds. A set of self-consistent model parameters for all phases in the system is obtained. This provides theoretical guidance for further study of the reaction between SiO2 and rare earth.

O-20: Uncertainty Quantification and Propagation in CALPHAD Modeling: Brandon Bocklund1; Richard Otis2; Zi-Kui Liu1; 1Pennsylvania State University; 2Jet Propulsion Laboratory, California Institute of Technology
     CALPHAD modeling is a core tool for materials design because of its demonstrated ability to extrapolate unary, binary, and ternary thermodynamic assessments to describe multi-component thermodynamics. The inverse pyramid dependence of multi-component CALPHAD databases on their constituent low-order assessments makes it challenging to develop or update large multi-component databases. CALPHAD databases available today are point estimates of the knowledge of a system and do not convey any uncertainty that arises from the choice of models and the uncertainty in the data used to parameterize the models.Recently, we developed ESPEI (Extensible Self-optimizing Phase Equilibria Infrastructure) as a platform for studying and applying Bayesian inference methods to performing CALPHAD assessments and uncertainty quantification for arbitrary Gibbs energy models. This presentation will discuss considerations and challenges for uncertainty quantification in CALPHAD modeling, examples of uncertainty propagation to computed thermodynamic properties, and strategies for widespread adoption of Bayesian inference approaches in CALPHAD modeling.