Hume-Rothery Symposium: Accelerated Measurements and Predictions of Thermodynamics and Kinetics for Materials Design and Discovery: Session IV
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 2:00 PM
March 16, 2021
Room: RM 35
Location: TMS2021 Virtual
Session Chair: Dana Frankel, QuesTek Innovations LLC
2:00 PM Invited
High-throughput Synthesis, Characterization and Prediction of Metallic Glass Formation: John Perepezko1; Janine Erickson1; Dan Thoma1; Carter Francis1; Paul Voyles1; Benjamin Afflerbach1; Dane Morgan1; 1University of Wisconsin-Madison
Materials discovery in metallic glass research is limited by the speed of synthesis and the need for experimental data for any model to predict glass formation. Additive manufacturing (AM) provides cooling rates of 103-104 K/s for bulk metallic glass (BMG) formation. In situ alloying enables rapid synthesis of compositional libraries with larger sample sizes than are provided by combinatorial thin films. As a test of the method, elemental powders were used to synthesize alloys in the known glass-forming system Mg-Cu-Y. With disparate melting temperatures, high reactivity, and dissimilar physical and thermal properties this system presents several challenges for AM. Using a tiered high-throughput characterization system, amorphous material was identified in a region of known BMG formation. In parallel with the AM, machine learning was applied to correlate a large database of critical cooling rates with elemental features to predict a favorable glass forming composition range that was confirmed by experiment.
2:40 PM Invited
A Thermodynamic and Molar Volume Database for Co-base Superalloys: Ursula Kattner1; Peisheng Wang2; 1National Institute of Standards and Technology; 2Central South University
The properties of both gamma/gamma’ Ni-base and Co-base superalloys are mainly the result of the characteristic gamma/gamma’ microstructure. However, the temperature ranges for the stability of the gamma’ phase are to a large extent different between these two alloy families. Knowledge of the phase equilibria in these systems is essential for the identification of promising alloy candidates and their processing requirements. The CALPHAD method is a well-established tool for obtaining such information. While free thermodynamic databases are available for Ni-base superalloys none is currently available for Co-base superalloys. As part of the CHiMaD/NIST project, a database for Co-base gamma/gamma’ superalloys is being developed. The database will include description of the Gibbs energy and molar volume as functions of temperature and composition. The model parameters are assessed using data from experimental measurements and theoretical predictions, such as density functional theory. This presentation will report on the current state of the database.
3:20 PM Invited
Phase Stability and Kinetic Considerations in Materials Processing and Performance: Steven Zinkle1; Yajie Zhao1; Ty Austin1; Ying Yang1; 1University of Tennessee
Accelerated development of high performance structural alloys is important for multiple applications including utility-scale fossil and nuclear energy systems as well as advanced aerospace systems. This presentation will summarize recent fundamental and applied research results that are relevant for accelerated design and discovery of advanced structural materials. Examples of fundamental questions being explored using ion beam bombardment as a convenient diagnostic probe include: how quickly can nanoscale volumes respond to rapid temperature quenches and re-establish thermal equilibrium phases; relevance of ion beam dynamic ballistic dissolution and radiation enhanced renucleation and growth processes for understanding precipitation kinetics; and utilization of implanted inert marker atoms to examine vacancy-driven thermal creep phenomena. Recent progress using directed energy deposition to fabricate oxide dispersion strengthened FeCrAl will be summarized, along with a comparison of conventional and field assisting sintering technologies to fabricate a novel creep-resistant high conductivity Cu alloy designed by computational thermodynamics.
4:00 PM Invited
Machine Learning-assisted ICME Approaches to Explore the Alloy and Process Space in Metals Additive Manufacturing: Raymundo Arroyave1; 1Texas A&M University
To date, the vast majority of work on metal AM has been framed in terms of the need to tune processing conditions for the AM of X alloys, where X stands for conventional alloy classes (e.g. SS316L, IN718, Ti64, etc). This approach often overlooks the fact that historically, every engineering alloy has been designed with a processing route in mind. The question then is how best to approach the alloy design problem from a perspective that incorporates notions of printability or processability. In this talk, I will introduce our efforts to tackle the alloy design problem while explicitly considering alloy features associated with the suitability of a given alloy to be printed using laser powder bed fusion (LPBF). Our framework combines physics-based models, CALPHAD phase stability predictions, machine learning, Bayesian optimal experimental design. We apply our framework on the discovery of potentially printable refractory high entropy alloys.
4:40 PM Invited
Printability and Properties of Metallic Alloys for Laser Powder Bed Fusion Additive Manufacturing: Yongho Sohn1; Le Zhou1; Holden Hyer1; Abhishek Mehta1; 1University of Central Florida
Laser powder bed fusion (LPBF) of metallic alloys is a transformative technology that can produce net-shape components with nearly unlimited geometrical complexity and customization. This technology also brings an opportunity to develop new and modified alloys specifically for LPBF, which warrants fundamental understanding of phase stability, diffusion kinetics and solidification so that the dependent process variables are desensitized for printability, and thermo-kinetic environment associated with LPBF are effectively utilized to optimize the functional properties. Selected observations of microstructural development in LPBF, such as grain structure, composition-sensitive solidification cracking, sub-grain micro-segregation, homogenization, and precipitation will be highlighted for additively manufactured Al-alloys, produced from gas atomized alloy powders made for both commercial and experimental applications. Practical use of phase diagrams and diffusion kinetics in designing and modifying the alloy composition for the enhanced buildability and properties will be presented with experimental corroboration.