Materials Genome, CALPHAD, and a Career over the Span of 20, 50, and 60 Years: An FMD/SMD Symposium in Honor of Zi-Kui Liu: Kinetics
Sponsored by: TMS Functional Materials Division, TMS Structural Materials Division, TMS Materials Processing and Manufacturing Division, TMS: Alloy Phases Committee, TMS: Integrated Computational Materials Engineering Committee
Program Organizers: Yu Zhong, Worcester Polytechnic Institute; Richard Otis, Jet Propulsion Laboratory; Bi-Cheng Zhou, University of Virginia; Chelsey Hargather, New Mexico Institute of Mining and Technology; James Saal, Citrine Informatics; Carelyn Campbell, National Institute of Standards and Technology
Wednesday 8:30 AM
March 22, 2023
Room: Sapphire L
Location: Hilton
Session Chair: Carelyn Campbell, National Institute of Standards and Technology
8:30 AM Invited
About 25 Years of Diffusion-multiple Experiments as Input to CALPHAD: Ji-Cheng Zhao1; 1University of Maryland
Diffusion multiples have been employed for about 25 years to perform high-throughput and reliable measurements of phase diagrams, diffusion coefficients, and composition-dependent properties including thermal conductivity, specific heat, thermal expansion, magnetic properties, hardness, and elastic constants. The data so obtained have been reliable input to CALPHAD modeling over the years for several alloy systems. Dual-anneal diffusion multiples yielded vast amount of precipitate microstructure as a function of composition, temperature, and time; and will be an opulent ground for coupled experimental-modeling studies to advance the precipitation modeling, including sequential precipitation of multiple phases. A potpourri of my favorite experiments will be shown to illustrate the power of diffusion multiples as input to CALPHAD. Future prospective will also be touched upon, especially in relation to the integration of modeling and experiments.
9:00 AM Invited
Selected Observations in Magnesium Alloys: From Diffusion Couples to Laser Powder Bed Fusion: Yongho Sohn1; 1University of Central Florida
Magnesium alloyed with Al, Zn, and Rare Earth (RE) is of great practical interests owing to their strength-to-weight ratio and bioresorbability. Alloy design based on thermo-kinetic foundation coupled with additive manufacturing can enhance the adoption of Mg-alloys in various engineering applications. This talk will highlight selected experimental observations from isothermal diffusion couple investigations in several binary and ternary systems, and analytical findings based on irreversible thermodynamics. Integration into computational materials tools invoking concepts such as “materials genome” and “CALPHAD” will be discussed based on identifying the critical needs for fundamental experimental data and observations, which would accelerate the pace of computational materials engineering including machine learning as “learning” data/results. In addition, recent progress in additive manufacturing, specifically laser powder bed fusion of Mg-alloys, such as WE43, Mg-Ce and Mg-Ce-Mg alloys, will be presented in terms of their buildability, properties and microstructural development, along with findings from various lattice structure.
9:30 AM Invited
Additive Manufacturing of Steels – Application of Computational Thermodynamics and Kinetics to Alloy Development: Greta Lindwall1; Chia-Ying Chou1; Hans-Henrik König1; Niklas Holländer Pettersson1; Chrysoula Ioannidou1; Ethan Sullivan1; 1KTH Royal Institute of Technology
A combination of Calphad-based computational tools is applied to study the microstructure evolution during additive manufacturing (AM) of steels. The computational investigations are integrated with advanced materials characterization techniques for model validation and calibration with the goal to develop a computational framework for AM steel design. Examples of our ongoing research activities will be presented with focus on the solidification behavior, solid-state phase transformation and precipitation kinetics during laser- or electron beam-powder bed fusion and post-process heat treatment of martensitic hot-work tool steels.
10:00 AM Break
10:20 AM Invited
High Temperature Creep Induced Phase Transformation in Austenitic Stainless Steels: Guocai Chai1; Joakim Odqvist2; 1Alleima; 2KTH
Microstructures of two heat resistant austenitic stainless steels after long term ageing and creep testing have been studied using thermodynamic calculations and electron microscopy techniques. Martensitic phases have been observed in both steels. 17Cr10Ni austenitic steel was creep-tested at 800°C. Formation of martensite is mainly due to the precipitation of Cr2N. The consumption of Cr content in the matrix leads to an increase in Ms temperature and consequently formation of martensite. 18Cr8Ni austenitic steel was creep-tested at 600°C. Formation of martensite in this steel is mainly due to local depletion of Cr and Ni near the grain boundary due to different types of intermetallic precipitates, which causes an increase of Ms temperature. The influence of stress or strain on the precipitation is studied by an extra energy added to the Gibbs energy of the austenite phase to predict the precipitation behaviours by comparing with the aged materials.
10:50 AM Invited
Materials Modelling for Metals Processing: Jianguo Lin1; Zhusheng Shi1; 1Imperial College London
Controlling failure and lifetimes of engineering components due to fatigue and creep are extremely important in engineering applications and light-weighting designs. These are related to the control of key metallurgical states and mechanical properties at key locations within components, which are normally achieved via thermal-mechanical processing, i.e., forming/shaping processes, of engineering components. Thus, creating an ability to simulate a wide range of high temperature metal forming processes to predict microstructure and mechanical property evolution and distributions of formed parts becomes more important. To achieve this, physically based unified viscoplastic constitutive equations enabling to model the dynamic interaction between viscoplastic flow and microstructure evolution need to be developed, which include grain growth, recrystallisation, precipitation and dislocation. In this presentation, the microstructure evolution, development of physically based viscoplastic constitutive equations, and the procedures for the determinations of the constitutive equations will be discussed.