Advanced Materials for Harsh Environments: Session II
Program Organizers: Navin Manjooran, Solve; Gary Pickrell, Virginia Tech
Wednesday 2:00 PM
October 4, 2023
Room: A120
Location: Greater Columbus Convention Center
Session Chair: Xiao Li, University Of North Texas; Navin Manjooran, Chairman, Solve; Gary Pickrell, Virginia Tech
2:00 PM Invited
Virtual Characterization Tools for Understanding Material Response in Harsh Conditions: Avanish Mishra1; 1Los Alamos National Laboratory
Microstructural characterization during deformation is vital for the understanding of material response and quantifying aging effects on strength. Traditional post-mortem techniques, while valuable, are limited in their ability to unravel complex mechanistic histories. Advanced real-time, non-destructive techniques like Bragg Coherent Diffraction Imaging (BCDI) can offer insights beyond these limitations, but they are often limited by uncertainties in the phase angle and the inversion process. To address these issues, atomistic simulations have been used to supply bounds on the missing information, where they are relatively inexpensive, statistically robust, and capable of mirroring experimental timescales. However, the lack of complementary characterization tools often limits the direct corroboration of modeling and experimental observations. This presentation explores the development and application of virtual characterization tools for materials subjected to harsh conditions. The focus will be on the observed correlation and the ability to fingerprint diffraction patterns of dynamically deformed materials. Additionally, the presentation will explain the enhancement of data extraction from advanced X-ray sources in near- and mid-field regimes. Lastly, the development of a novel virtual texture analysis tool, "VirTex," will be discussed, demonstrating its ability to decode phase transformation and twinning mechanisms in polycrystalline microstructures.
2:20 PM Invited
Blue Phase Liquid Crystal Templated Nucleation and Growth of Inorganic Materials: Tejal Pawale1; Xiao Li1; 1University of North Texas
Materials with complex 3D morphologies have broad applications in photonic crystals, filtration, sensing, biomedicine, metamaterials, and catalysis as well as energy conversion and storage. Such applications are enabled by the materials’ high surface-to-volume ratio, improved connectivity, functional pore interface, adjustable pore accessibility, and mechanical stability. Sophisticated 3D mesostructures with critical lattice orientations, transport pathways, and chemical compositions in bulk materials provide an effective platform for revealing the relationship between structure and properties. The unique properties of soft materials—large response to small perturbations, self-assembled ordered structure, low energy consumption for altering structure—make them widely used to create controllable 3D structures. However, due to the inherently weak mechanical property, soft materials usually can’t withstand harsh engineering conditions, such as high temperature, stress or chemical environments. Here, we rely on blue phase liquid crystals, which combine the order of solid molecular crystals and the fluidity of liquids, giving them highly ordered 3D cubic symmetries and rapid assembly kinetics.
2:40 PM Invited
Smart Phase Transforming Metal Ceramic Multilayers: Carter Stotts1; Michael Large1; Gregory Thompson1; Christopher Weinberger1; 1Colorado State University
Ultrahigh temperature environments require materials that have a combination of strength and high melting temperatures. However, these properties usually make materials brittle and fracture prone at low to moderate temperatures where resistance to fracture is needed. In this talk, we introduce metal-composite ceramic that can be fracture resistant at low temperatures but phase transforms to a UHTC at high temperatures. Specifically, we shown how transition metal carbide/transition metal multilayers can be designed to phase transform from a composite to a monolithic ceramic that has UHTC properties and creep resistance. This is accomplished by integrating computational modeling of the phase transformation, theoretical modeling of the fracture resistance, and experimental demonstration of the phase transformation properties. We further demonstrate how these materials can be optimized for the phase transformations and how the can be synthesized from standard UHTC processing routes.
3:00 PM
Behavior of Select Refractories in Plastics Gasification Environments: Omer Dogan1; Griffin Patterson2; Kristin Tippey1; Jinichiro Nakano1; Anna Nakano1; Hugh Thomas1; 1National Energy Technology Laboratory; 2Harbison Walker International
One of the advantages of plastic gasification is its ability to accommodate a variety of feedstock selections and plastic mixes. Significant energy savings in recycling plastics would be possible not only compared to the mechanical recycling but also to the traditional gasification because plastics carry higher heating values than traditional carbon feedstocks. The sustainability of such a process, however, requires overcoming certain operational challenges with refractory liner performance with respect to novel slag chemistry and properties as introduced by plastic ashes. The plastic ashes tend to be rich in alkaline earth metals such as Ca and Mg. In this work, synthetic plastic slag was interacted with select refractory bricks designed and manufactured by HWI in simulated gasification environments at 1500 °C. The paper will discuss refractory behavior against plastic slag including slag penetration, interfaces, and refractory degradation mechanism.
3:20 PM
Castable Eutectic Ni-Ce Superalloys Strengthened by a γ/γʹ Microstructure: S. Bushra Haider1; Elizabeth Heon1; Eric Lass1; 1University of Tennessee-Knoxville
Ni-based superalloys are the premier material for high-temperature applications but are often difficult to manufacture via solidification-based processing. Eutectic alloys typically possess good castability due to narrow solidification ranges. The Ni-Ce system possesses a eutectic reaction but has never been examined as a potential high-temperature material. This work investigates the microstructure and mechanical properties of near-eutectic alloys Ni-17Ce and Ni-17Ce-5Al (wt. %). Both alloys show outstanding high-temperature microstructure and mechanical property stability at 900 °C. The formation of Ni3Al (γʹ) precipitates is observed in the primary FCC-Ni phase of the ternary Ni-Ce-Al alloy. The precipitation hardened ternary alloy exhibits superior hardness to Inconel 718 at elevated temperatures, retaining its strength to 750 °C, or about 50 °C higher than Inconel 718. The novel hierarchical microstructure consisting of thermally stable eutectic regions combined with γʹ-strengthened primary FCC-Ni and eutectic phases show great promise as a castable material solution for high-temperature applications.
3:40 PM Break
4:00 PM Cancelled
Computational Design of Yttrium-Rare Earth Alloyed Disilicates as Environmental Barrier Coatings: Shiqiang Hao1; Richard Oleksak1; Ömer Doğan1; Michael Gao1; 1National Energy Technology Laboratory
The development of advanced environmental barrier coating materials possessing integrated thermal-mechanical functions is crucial to protect SiC-based ceramic composites from chemical and thermal attack for better performance of components in the hot section of gas turbine engines. We utilize density functional theory together with combinatorial chemistry methodology to design β-Y2Si2O7-based alloyed systems for desired coefficient of thermal expansion (CTE) and low lattice thermal conductivity. Phonon calculations within the quasi-harmonic approximation were used to determine CTE, while Debye-Callaway model was used to evaluate the thermal conductivities. Results show that the solid solution of YYbSi2O7 exhibits lowered thermal conductivity than pure cases and a good range of CTE. Furthermore, we present good candidate materials of Er1/4Lu1/4Y3/4Yb3/4Si2O7 and Er1/2Lu1/2Y1/2Yb1/2Si2O7, with very low thermal conductivity and a good match of CTE with SiC. These properties are believed to enable efficient increases in the performance of protective components in gas turbines.
4:20 PM
Effect of Heat Treatment on Grain Boundary Characteristics and Intergranular Creep Resistance of IN740H and It's Variant: CheolHyeok Yang1; DongMin Kim1; ChiWon Kim1; HiWon Jeong2; HyunUk Hong1; 1Changwon University; 2Korea Institute of Materials Science
In this study, three heat treatments were designed based on thermodynamic analysis of Inconel 740H, considered material for A-USC steam turbines. After long-term thermal exposure(750 ℃) for 5,000h, the stability of microstructure and mechanical properties was confirmed, and factor that optimize creep properties were derived through the creep test(750 ℃/270MPa). It was confirmed that the content of Cr was concentrated at the MC carbide interface. The MC carbide has increased creep properties because temperature and stress during creep contribute to the Decomposition(MC + γ →M23C6 + γ') for phase transformation. In the case of superalloy developed within the component range of Inconel 740H, the difference in phase transformation was confirmed through thermodynamic analysis. After heat treatment, the grain boundary microstructure was also different. This difference led to a result that continuous distribution and blocky type of carbide induced optimizing the grain boundary deformation by dislocation gliding after the creep(750 ℃/270MPa).
4:40 PM
Cold-rolled 3D Graphene Sheets as a Protective Material in the Fluorocarbon Plasma Environment: Vamsi Krishna Reddy Kondapalli1; Kyle Brittingham1; Guangqi Zhang1; Mahnoosh Khosravifar1; Vesselin Shanov1; 1University of Cincinnati
Processing of electronic components in a fluorocarbon plasma environment causes deteriorating corrosion of the dry etch chambers. Ceramics like SiO2 and Al2O3 offer high corrosion resistance and chemical stability. However, their interaction with ionized fluorocarbon gases causes chamber contamination due to erosion and particle generation. Here we propose cold-rolled 3D graphene as an alternative reusable protective material to prevent corrosion of silicon and SiO2 surfaces used in dry etching equipment. 3D graphene (3DG) synthesized via Chemical Vapor Deposition (CVD) is scalable and can be processed into various shapes and sizes. The high surface area and internal porosity of 3DG affect its etch resistance, whereas cold rolling suppresses the porosity and increases the gravimetric density by 37.3 times. Cold-rolled 3DG sheets demonstrated significantly higher etch selectivity to silicon/ SiO2 in comparison to that of pristine 3DG when exposed to a CF4 plasma environment at 100W and 300W power.
5:00 PM
Doped Lanthanum Chromite-refractory Based Composites Sensors for High Temperature Monitoring in Harsh Environments Systems: Javier Mena1; Edward Sabolsky1; Konstantinos Sierros1; Katarzyna Sabolsky1; Rowan Barto1; Nicholas Voorstad1; 1West Virginia University
In order to test and monitor the operational stability and conditions of various energy, and manufacturing systems and their components, development of accurate sensors capable of operating at temperatures in excess of 1000 °C in various environments for long durations is required. In addition, many of these harsh-environment systems do not permit sensors to be directly inserted due to possible undesirable chemical interactions. In this work were developed high-temperature sensors using doped lanthanum chromites-refractory based composites synthesized by a mixed-oxide route. Different electrode printing approaches were explored. The chemical stability of the sensors was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The Seebeck coefficients were determined by thermoelectric voltages measurements at temperature up to 1400 °C.