Hume-Rothery Symposium: Accelerated Measurements and Predictions of Thermodynamics and Kinetics for Materials Design and Discovery: Session II
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
Monday 2:00 PM
March 15, 2021
Room: RM 35
Location: TMS2021 Virtual
Session Chair: Wei Chen, Illinois Institute of Technology
2:00 PM Invited
An Atom-Probe Tomogaphy Study of the Temporal Evolution of Concentration Retention Excesses and Depletions at gamma-f.c.c/gamma-prime-L12 Interfaces in a Ni-Al-Cr-Re Superalloy: David Seidman1; 1Northwestern University
The coarsening kinetics of coherent gamma-prime-L12-precipitates in a Ni–10Al-8.5Cr-2Re at.% alloy aged at 973 K from 0 to 1024 h are studied utilizing atom-probe tomography and diffusion theory. The temporal evolutions of concentration retention excesses and depletions at the gamma-f.c.c/gamma-prime interfaces are presented. The compositional trajectories of both phases are presented in the Ni-Al-Cr-Re phase-diagram as represented in a tetrahedron. The gamma-prime phase is nucleated in the gamma-prime-phase field. Its composition trajectory encompasses nucleation, growth, and coarsening. The tie-line between the gamma- and gamma-prime-phases is determined by the end-point compositions of the two-phases on the two conjugate solvus surfaces. The composition trajectories of both phases are curvilinear. To explain this common phenomenon in the three Ni-based alloys (Ni-Al, Ni-Al-Cr, and Ni-Al-Cr-Re) it is necessary to include the off-diagonal terms in the diffusivity matrices, which give rise to solvent-solute and solute-solute flux couplings.
2:40 PM Invited
Extended Applications of the CALPHAD Simulations: Fan Zhang1; Duchao Lv1; Weisheng Cao1; Shuanglin Chen1; Chuan Zhang1; Songmao Liang1; 1CompuTherm LLC
Computer simulation has played an important role in accelerated materials design and development. Among various types of science-based models and methods, the CALPHAD approach has been recognized as a key building block of ICME due to its successful application to technically important multi-component systems. The capability of the CALPHAD-type of modeling tools goes beyond phase diagram calculations and extends to a variety of materials science and engineering fields. To further enhance the power of the CALPHAD approach, efficient use of the simulated phase-related data and effective integration of these data with advanced models is key. New features of the Pandat software for high throughput calculation, processing and visualizing the simulated results through Python, and integration with Phase Field simulation will be shown in this presentation. Application examples will be presented for a variety of alloys, including Al-based alloys, Ni-based alloys, as well as high entropy alloys.
3:20 PM Invited
Computational Modeling-assisted Development of Cast Alumina-forming Austenitic Stainless Steels for High Temperature Corrosive Environments: Govindarajan Muralidharan1; Yukinori Yamamoto1; Michael Brady1; Shivakant Shukla1; Tanya Ros2; Stanley Fauske3; Roman Pankiw4; Jim Myers5; 1Oak Ridge National Laboratory; 2Arcelor Mittal Global R & D; 3Arcelor Mittal Coatesville; 4Duraloy Technologies; 5Metaltek International
Cast chromia-forming austenitic stainless steels such as HP-type alloys are used in a wide range of industrial applications such as high temperature furnace components, radiant burner tubes, and ethylene cracking furnaces that demand high temperature microstructural stability, corrosion resistance, and creep strength. Although alumina scales offer better corrosion protection at these temperatures, developing cast austenitic alloys that form a stable alumina scale and achieve creep strength comparable to existing cast chromia-forming alloys, has been challenging. This work outlines our recent work on the development of cast Fe-Ni-Cr-Al austenitic stainless steels for use in high temperature industrial and chemical environments as an alternative to cast chromia-forming cast austenitic stainless steels using computational thermodynamic modeling and laboratory scale validation. This talk will highlight the challenges in design and in scale-up. Research sponsored by ARPA-E, US Department of Energy, under Contract DE-AC05-00OR22725 with UT-Battelle, LLC.
4:00 PM Invited
Visualizing and Rationalizing Synthesis Pathways in Oxides: Gerbrand Ceder1; 1University of California, Berkeley
Being able to rationalize and predict which metastable intermediates form during solid-state reactions is crucial towards developing computable frameworks for predictive synthesis. Using NaxMO2 layered oxides (M = Co, Mn) as an example we use in-situ experiments and ab-initio calculations to rationalize the complex pathway of stable and metastable phases that is observed to form along the pathway towards the final equilibrium state. We demonstrate that the presumed low temperature equilibrium states are actually metastable, and form as the result of a complex pathway that is set by the first phase that forms in the system. This phase seems to be selected by an optimization of Gibbs free energy, but under compositional constraint conditions which are different from the ones imposed on the overall reaction vessel. Remarkably, we find that we can predictively modify the reaction pathway, and therefore the metastable phases that form, simply by changing the precursor materials.
4:40 PM Invited
High-throughput Testing and Characterization of Novel Additive Manufactured Materials: Madelyn Madrigal-Camacho1; Adam Freund1; Kendrick Mensink1; Guillermo Aguilar1; Suveen Mathaudhu1; 1University of California, Riverside
Critical to the future advancement of additive manufacturing (AM) technologies is the exploration of fundamental laser-material interaction paired with informed alloy powder development. The large-scale and "black-box" nature of commercial 3D printers limits the ability to pursue such studies due to powder and process control limitations. In this work, we will present our efforts to literally, out-of-the-box, probe fundamental AM process-microstructure-property correlations. The primary tool to pursue this consists of a suite of lasers in pump-probe configurations that interact with small (5g-10g) of layered powder materials in a controlled atmosphere, heated environment. The resulting densified materials can be interrogated for density, hardness, phase structures (XRD) and microstructural evolution, and other physical properties with a minimal volume of material. Further, novel alloy compositions can be rapidly and easily explored. Preliminary examples of this approach will be presented for conventional AM alloy compositions along with novel nanocrystalline alloy printed materials.