Hume-Rothery Symposium: Accelerated Measurements and Predictions of Thermodynamics and Kinetics for Materials Design and Discovery: Session III
Sponsored by: TMS Structural Materials Division, TMS: Alloy Phases Committee
Program Organizers: Wei Xiong, University of Pittsburgh; Shuanglin Chen, CompuTherm LLC; Wei Chen, University At Buffalo; James Saal, Citrine Informatics; Greta Lindwall, KTH Royal Institute of Technology
Tuesday 8:30 AM
March 16, 2021
Room: RM 35
Location: TMS2021 Virtual
Session Chair: Wei Zhong, University of Maryland
8:30 AM Invited
Unexpected Phenomena Observed in Metallurgical Studies: Sinn-wen Chen1; 1National Tsing Hua University
Some unexpected phenomena observed in metallurgical studies are discussed. These phenomena include cruciform pattern formation, flat shuriken shape formation, whisker formation, solid state amorphization, woven structure formation and liquation. Cruciform patterns are found in the Sn/Te reaction couples reacted at 250℃ and in the Sn/Co couples reacted at 200°C. Instead of forming cruciform patterns, flat shuriken shape phases are observed at reentrant corners. Whiskers of pure Ag as long as 10 cm are found in Ag-In-Se alloys. Striations and faceted microstructures are observed. Similarly, Ag and Cu whiskers are observed in the annealed Ag-Cu-Te alloys with different compositions. In the Sn/Ni–7.0wt.%V reaction at 200℃, solid state amorphization reaction occurs and an amorphous T phase layer is formed. Peculiar woven microstructure is observed in the Sn-3.0 at.%Co-77.0 at.% Cu. The formation mechanism is understood by directionally solidified samples. Liquation observed in various kinds of solid/solid reactions are reported and analyzed.
9:10 AM Invited
High-throughput Hot-isostatic-pressing Micro-synthesis for Accelerated Studies of High Entropy Alloys: Lei Zhao1; Shuying Chen2; Zi Wang3; Lixia Yang1; Hui Wang1; Haizhou Wang1; Liang Jiang2; 1Central Iron & Steel Research Institute, China; 2Yantai University; 3Central South University
A high-throughput experimental method is developed to study the high entropy alloys (HEAs) based on the powder metallurgy sintering approach. The high-throughput Hot-Isostatic Pressing (HIP) micro-synthesis method utilize elemental powders, laser-based additive manufacturing, HIP and heat treatment processes to form more than 80 bulk HEAs with various chemistry. These combinatorial HEAs contain 13 elements, including Fe, Cr, Co, Ni, Mo, Mn, W, Si, Nb, Ti, Ta, Cu, and Al. There are 18 types of material system among these HEAs. They are characterized by different high-throughput analyzing methods, such as LIBS, micro-XRF, Full-View-Metallography, SEM, micro-XRD and Scanning-Micro-Hardness etc. The effects of chemistry on microstructure and property are studied via experiments and theoretical modeling. This work put forth a new high-throughput HIP micro-synthesis approach for accelerating the design and screening of bulk HEAs and other materials.
9:50 AM Invited
Integration of Computational Tools and Advanced Characterization Methods to Understand Phase Transformations in Additively Manufactured Steels: Greta Lindwall1; Niklas Holländer Pettersson1; Chia-Ying Chou1; Durga Ananthanarayanan1; Benjamin Neding1; Peter Hedström1; Fan Zhang2; 1KTH Royal Institute of Technology; 2NIST
Additive manufacturing (AM) enables complex tool geometries with improved tool performance as a result. This has, in particular, increased the interest in developing printable medium-carbon steels aimed for hot-work tooling application where the incorporation of conformal cooling channels in the tool design may prolong the tool life considerably. In this work, the as-built microstructures of hot-work tool steels manufactured using laser-powder bed fusion are studied in detail as well as the response to post-print heat treatments. Emphasis is on how Calphad-based computational thermodynamics and kinetics can be applied for materials design and development of suitable post-heat treatments. Experimental characterization methods including ex-situ and in-situ synchrotron-based diffraction are employed for model calibration. Protocols for quantifications of retained austenite fractions in AM tool steels accounting for texture and spatial variations are discussed.
10:30 AM Invited
Computational Thermodynamics and Its Applications: Zi-Kui Liu1; 1Pennsylvania State University
Thermodynamics concerns the energetics of configurations in a system. In this presentation, recent progresses in computational thermodynamics are discussed along with challenges and impacts. Computational thermodynamics enables the modeling of thermodynamics of a configuration as a function of both external and internal variables and the calculations of properties in terms of first and second derivatives of energy. Consequently, external constraints such as fixed strain and internal degree of freedoms such as defects can be described in a coherent framework and applied to materials design. Two important but largely overlooked aspects will be discussed, i.e. the application of statistical thermodynamics with the probability of configurations and their contributions to system properties, and the applications of second derivatives of energy with respect to either two extensive variables or two potentials or a mixture of them in understanding and predicting critical phenomena, emergent behaviors, kinetic coefficients, and mechanical properties.
11:10 AM Invited
High-throughput Experiments and Machine Learning Modeling for Designing Next Generation Superalloys: Akane Suzuki1; Chen Shen1; 1GE Research
High-throughput experiments and machine learning modeling are increasingly becoming essential tools for efficiently and successfully designing new alloy chemistries that are tailored to achieve desired combinations of properties. In this talk, we will present examples of applying high-throughput experiments using diffusion multiples and machine learning modeling of physical, mechanical and environmental properties using historical and/or new datasets in designing next generation Ni-based and Co-based superalloys for industrial power generation gas turbines and aircraft engines. Current limitations of these tools and challenges for future industrial applications will be discussed.