Hume-Rothery Symposium: Thermodynamics, Phase Equilibria and Kinetics for Materials Design and Engineering: Applications
Sponsored by: TMS Structural Materials Division, TMS: Alloy Phases Committee, TMS: Integrated Computational Materials Engineering Committee
Program Organizers: Carelyn Campbell, National Institute of Standards and Technology; Michael Gao, National Energy Technology Laboratory; Wei Xiong, University of Pittsburgh
Tuesday 8:30 AM
February 25, 2020
Room: 32A
Location: San Diego Convention Ctr
Session Chair: Carelyn Campbell, National Institute of Standards and Technology; Greta Lindwall, KTH Royal Institute of Technology
8:30 AM Invited
Industrial Applications of Thermodynamic and Kinetics Modeling: David Furrer1; Dmitri Novikov1; Xuan Liu1; Sergei Burlatsky2; 1Pratt & Whitney; 2United Technologies Research Center
Thermodynamic modeling tools and methods have evolved extensively. The ability to predict the equilibrium and non-equilibrium constitution of materials has enabled the capability to design and develop materials for next generation applications. These capabilities have allowed virtual experiments to guide focused, rapid physical investigations to achieve new combinations of properties in industrial relevant materials. The use of thermodynamic and kinetics modeling are helping to answer many questions and devise solutions to many challenging industrial issues. While there was a period of time when consolidation of material types was desired due to the cost of material design, development and validation, modeling tool are now breaking down this barrier and enabling implementation of unique material solutions for unique challenges. Examples of how thermodynamic and kinetics modeling tools are being applied to industrial applications will be discussed.
9:10 AM Invited
Application of Calphad-based Computational Tools to Alloy Development for Additive Manufacturing: Greta Lindwall1; Durga Ananthanarayana1; Chia-Ying Chou1; Niklas Holländer Pettersson1; ; 1KTH Royal Institute of Technology
This talk concentrates on the practical use of the Calphad method to understand and predict the microstructure evolution during metal additive manufacturing (AM). A very limited number of the commercially available alloys are printable and to meet the urgent demand for new AM alloys, the use of computational tools that accounts for Calphad descriptions of multicomponent materials data is essential.A brief review of how Calphad descriptions and Calphad-based computational tools currently are being applied within the AM research field will be given. Examples of our ongoing research activities on AM modeling using Calphad-based tools will be presented including predictions of the as-built microstructure of medium carbon tool steels and the effect of inoculation during AM of stainless steels. Finally, an outlook of how the Calphad method could be further applied to assist in the AM alloy development will be discussed.
9:50 AM Invited
Calphad Applications and Challenges in Gas Turbine Coatings: Carlos Levi1; 1University of California, Santa Barbara
All materials of current interest for the hot section of advanced gas turbines require protective coatings to survive in extreme environments involving temperatures ≥1200°C, pressures ≥30 bar, high velocity moisture-laden combustion gases and multiple contaminants, especially siliceous debris ingested with the intake air. The coatings generally involve two or more layers designed to provide thermal insulation as well as protection against environmental attack including oxidation, moisture-enhanced volatilization, as well as penetration and/or dissolution by silicate glassy melts generically known as CMAS. This presentation will discuss the role of phase diagrams and Calphad tools in understanding problems of phase stability, interdiffusion and thermochemical interactions with extraneous deposits, as well as the ensuing thermomechanical effects, using examples from thermal and environmental barrier coatings. A major challenge is presented by increasing chemical complexity of the systems, which may involve stacks of multiple coating materials, with melts containing at least five relevant chemical species.
10:30 AM Break
10:50 AM Invited
Phase Equilibria in High-entropy and Complex-concentrated Alloys: Daniel Miracle1; 1Air Force Research Laboratory
Phase equilibria plays a central role in the growing field of high-entropy alloys (HEAs) and complex, concentrated alloys (CCAs). The majority of HEAs and CCAs are reported in the as-cast condition, a growing number are characterized after some amount of homogenization, and a few experimental studies measure the phases present after long-term anneals that may approximate equilibrium conditions. These latter studies will be reviewed in this presentation, and results will be compared with appropriate commercial alloy families, especially regarding the extended gamma loop in the Fe-Ni-Cr system and the solid solution alloys common in refractory metals. The important role of computed phase diagrams will also be discussed.
11:30 AM Cancelled
Recent Progress in Constellium’s Thermodynamic & Kinetics
Simulation Approach: Christophe Sigli1; 1Constellium Technology Center
Recently, the new equilibrium routine Open Calphad (www.opencalphad.org) has been implemented in the Constellium internal thermodynamic software. This implementation drastically improves the overall calculation speed of demanding process simulations such as solidification with back-diffusion or homogenizing of as-cast concentration gradients during a heat treatment. Metastable phases are, generally, difficult to assess due to a lack of available equilibrium thermodynamic data. In order to evaluate them, the open source Density Functional Theory package Quantum Espresso (www.quantum-espresso.org) is used. When dealing with the kinetic of ordering reaction dominated by nucleation at low temperature (during the ageing of aluminium alloys for example), it is necessary to use a cluster expansion of the energy and a Kinetic Monte Carlo routine to describe early stages of precipitation. Examples illustrating the simulation approach at the different scales will be presented.