Refractory Metals 2023: Poster Session
Sponsored by: TMS Structural Materials Division, TMS: Refractory Metals & Materials Committee
Program Organizers: Brady Butler, US Army Research Laboratory; Todd Leonhardt, Rhenium Alloys Inc.; Matthew Osborne, Global Advanced Metals; Zachary Levin, Los Alamos National Laboratory
Tuesday 5:30 PM
March 21, 2023
Room: Exhibit Hall G
Location: SDCC
J-105: Accelerated Design of Radiation Tolerant Alloys for Nuclear Fusion: Matthew Lloyd1; Glenn Lim1; Mark Anderton2; Thomas Davis2; Michael Short3; Robert Simpson1; 1Singapore University of Technology and Design; 2Oxford Sigma Ltd.; 3Massachusetts Institute of Technology
High plant availability requirements and extreme operational conditions in future nuclear fusion reactors require the use of refractory materials such as W with attractive high temperature properties. Radiation induced effects, including transmutation, product precipitation, void formation, and dislocation loop formation, tend to degrade these attractive properties. New alloys, including some High Entropy Alloys (HEAs), have exhibited potentially useful properties. The wide compositional phase space in ternary, quaternary, and quinary alloys, combined with the large number of parameters associated with neutron irradiation make screening candidate materials extremely challenging. Rapid experimental screening of prototype alloys can accelerate the design, discovery, and development of potentially revolutionary new materials for use in fusion reactors. In this project, we aim to accelerate the initial stage of alloy development, by using composition-spread films and heavy-ion irradiation to quickly identify alloys that exhibit superior radiation tolerance using novel high-throughput techniques, such as transient grating spectroscopy.
J-93: An Additive Manufacturing System for High-resolution Composition Grading Combining Inkjet Deposition with Laser Powder Bed Fusion: Zachery Kutschke1; Ryan Penny1; Alexander O'Brien1; Emre Tekoglu1; Ju Li1; John Hart1; 1MIT
Capabilities to combine multiple metal and ceramic materials in single components, and to achieve desired gradients in composition, will advance the performance of future propulsion and energy conversion systems. Multi-material and gradient capabilities have been demonstrated for metals in additive manufacturing (AM) techniques; however, the spatial precision of composition control is limited for several reasons. We present a novel AM system for manufacturing compositionally graded components whereby an inkjet print head creates two-dimensional patterns in between layers of a laser powder bed fusion (LPBF) process. Nanoparticles in the ink combine with the base powder to achieve local in situ alloying. We discuss key design considerations for the system including thermal isolation of the inkjet system, temperature control of the build volume (up to 500C), and atmosphere control. The performance of the system is demonstrated through printing and characterization of gradient refractory composites using a Niobium-based powder as the feedstock.
J-94: Challenges in the Development of a Creep-Resistant Nb- Alloy Capable of 1300°C Service: Govindarajan Muralidharan1; Ying Yang1; Glenn Romanoski1; Roger Miller1; Thomas Muth1; George Ulrich1; 1Oak Ridge National Laboratory
There is significant interest in the development of Nb-based alloys for continuous use in turbine applications at 1300°C. These alloys are expected to have excellent high temperature creep properties, good room temperature strength and ductility, good processability, preferably be comparable in density to current Ni-based alloys, and be compatible with coatings that provide oxidation resistance at these temperatures. This presentation will highlight some of the challenges in developing Nb- alloys that possess the appropriate balance of properties. This work was supported by the US Department of Energy – ARPA-E ULTIMATE Program. This research was conducted by Oak Ridge National Laboratory, which is managed by UT Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE)
J-95: Fundamentals of Recrystallization in Binary Nb Alloys: William Waliser1; 1Colorado School of Mines
Nb3Sn superconductors are the most practical option for next-generation particle accelerator magnets. Recently, Hf additions to the base Nb alloy have be utilized to raise recrystallization temperatures above the Nb3Sn reaction treatment. This improves performance in the conductor by limiting the final Nb3Sn grain size. However, increased industry-wide Hf demand poses challenges for meeting future demands in particle accelerator projects, i.e. Future Circular Collider. Therefore, alternatives need to be identified for sustainability. A series of binary Nb-X alloys, including X=Ti, Zr, Hf, V, Ta, Mo, W, and Re, were fabricated and subjected to varying degrees of deformation. Static and dynamic recrystallization experiments were performed using the Gleeble thermomechanical simulator, and the resulting microstructure evolution was characterized with EBSD. Hardness measurements were also performed. This work expands upon the knowledgebase of how alloying elements affect microstructural evolution in Nb alloys for applications in superconductors and refractory multi-principal element alloys (RMPEAs).
J-104: Investigating Heat-treatment and Strain Path Effects on the Recrystallization of High-purity Niobium: Zackery Thune1; Conor McKinney1; Nathan Fleming1; Thomas Bieler1; 1Michigan State University
Improving accelerator performance relies on the consistent production of high-purity niobium superconducting radiofrequency (SRF) cavities. The current production standards involve a post-purification and recrystallization heat-treatment at 800°C for 3-hours; however, recent work has shown significant improvement in cavity performance when annealing between 900°C and 1000°C. Recrystallization is a thermally activated process, therefore increasing the annealing temperature and/or the heating rate should facilitate a greater reduction in the density of geometrically necessary dislocations (GNDs) which are strongly associated with the degradation of cavity performance via trapped magnetic flux. The goal of this study is to increase the SRF community’s understanding of the influence which annealing temperature, heating rate, and strain path have on the recrystallization behavior in high-purity niobium.
J-97: The Oxidation Behavior of the Eutectic Alloy Mo-20Si-52.8Ti in Dry and Wet Atmospheres: Matthias Weber1; Steven Schellert1; Hans-Jürgen Christ1; Aditya Tirunilai2; Alexander Kauffmann2; Martin Heilmaier2; Bronislava Gorr3; 1Universität Siegen; 2Karlsruhe Institut für Technologie (KIT IAM-WK); 3Karlsruhe Institut für Technologie (KIT IAM-AWP)
Mo-silicide based alloys with high Ti concentrations are a new class of high temperature materials with promising properties. The good oxidation resistance relies on the formation of a duplex titania-silica layer. In this contribution, the effect of water vapor on the formation and growth of oxide scales on the alloy Mo-20Si-52.8Ti (at. %) at 1200°C is investigated. The oxidation kinetics increases in wet atmospheres compared to that in dry air. To explore whether the outer TiO2 layer can diminish the detrimental effect of water vapor, this scale was removed which causes a dramatic acceleration of the scale growth kinetics in the wet environment. This was explained by the faster diffusion of water in silica compared to that of oxygen. It is discussed that water vapor may increase the pore density in silica, which further accelerates the diffusion of water and/or oxygen in silica.
J-98: Ultrahigh Temperature Testing Methodology for Refractory Alloys: Michael Patullo1; Arunima Banerjee1; Kevin Hemker1; 1Johns Hopkins University
Refractory alloys, including refractory multi-principal element alloys (R-MPEAs), have immense potential for use at ultrahigh temperatures and in extreme environments required for energy-efficient power generation, hypersonic flight, and space access. Improvements in single and polycrystalline R-MPEA growth and other novel alloy developments holds great promise, but the current scarcity of ultrahigh temperature tensile and creep experiments is a serious impediment. Recognizing the benefits associated with rapid characterization, a milli-scale high-throughput instrument has been developed to obtain the tensile and creep properties of ultrahigh temperature materials in high-vacuum and over a range of temperatures. Experiments involving a first-generation Senkov alloy, HfNbTaTiZr, will be used to demonstrate the efficacy of this new methodology. Results for a number of milli-scale refractory metals and alloys will be shared and used to elucidate the processing-structure-property relations that underpin their ultrahigh temperature mechanical behavior.