Advanced Materials for Harsh Environments: Session III
Sponsored by: ACerS Electronics Division
Program Organizers: Navin Manjooran, Solve; Gary Pickrell, Virginia Tech
Wednesday 8:00 AM
October 20, 2021
Room: A223
Location: Greater Columbus Convention Center
Session Chair: Gary Pickrell, Professor, Virginia Tech; Navin Manjooran, Chairman, Solve; Agnieszka Wusatowska-Sarnek, Commonwealth Fusion Systems
8:00 AM
Towards a Fundamental Understanding of Surface Interactions and Degradation Mechanism in Bio-feedstock-induced Corrosion: Soheil Daryadel1; Deborah Liu1; Hyosung An1; Samyukta Shrivastav1; Siddhesh Shevade2; Tom Eason2; Qian Chen1; Daniel Krogstad1; Jessica Krogstad1; 1University of Illinois at Urbana-Champaign; 2BP
The incorporation of bio-feedstock in fuel production due to the current global regulatory condition and net-zero emission targets fundamentally changes the refining process and affects the refinery infrastructure by introducing new and possibly more aggressive corrosion and degradation mechanisms. This presentation focuses on the interactions between bio-feedstock materials and structural surfaces to better understand the early-stage corrosion. High-throughput corrosion tests combined with metallurgical and chemical characterizations are employed to understand how bio-feedstocks encourage corrosion by identifying mechanisms linked to the intrinsic and extrinsic properties. The hydrolysis of triglycerides and the formation of free fatty acids in the bio-feedstock results in large carbon-rich aggregates at the surface, accelerated metal corrosion, which together give rise to carbon-rich corrosion products. Considering the complex nature of the processing and refinery conditions, this mechanistic insight can provide meaningful guidance towards the safe integration of highly sustainable, low-carbon feedstocks via existing processing infrastructure.
8:20 AM
High-temperature Stability and Phase Transformations of Titanium Carbide (Ti3C2Tx) MXene: Srinivasa Kartik Nemani1; Brian Wyatt1; Bowen Zhang1; Babak Anasori1; 1Integrated Nanosystems Development Institute (INDI), IUPUI
2D transition metal carbides/nitrides (MXenes) have been explored for energy storage and catalytic applications extensively. However, there is a gap in fundamental understanding of MXenes’ high-temperature phase stability in low oxygen, high-temperature environments. In this study, we evaluated stability of MXenes’ structure and morphology up to 1500 ᵒC in low-oxygen environments. We explored phase transformations in MXene thin films with in-situ x-ray diffraction (XRD) from 700ᵒ-1000 ᵒC and ex-situ annealing via spark plasma sintering. With these methods, we find that Ti3C2Tx MXene transforms to lamellar 3D crystalline ordered carbon vacancy TiCy and its superstructure Ti2C up to 1000 ᵒC and disordered carbon vacancy TiCy above 1000 ᵒC. The grain growth and transformation from nanolamellar hexagonal to lamellar cubic structures of titanium carbide is significant in realizing MXenes’ potential as high-temperature refractory ceramics when added as 2D additives in composites for high-temperature applications.
8:40 AM
Oxidation Behavior of IN100 Superalloy between 840 - 1120 K: Sebastian Lech1; Agnieszka Wusatowska-Sarnek2; Adam Kruk1; 1AGH University of Science and Technology; 2Pratt & Whitney
The study was devoted to the characterization of the oxide scale and near-surface region formed in IN100 superalloy during oxidation at temperatures between 840-1120 K for 1000 hours. The SEM, SEM-EDXS, TEM, STEM-EDXS and XRD methods were combined to obtain detailed information about the microstructure, morphology, phase- and chemical composition of the investigated superalloy. The study revealed that at the lowest temperature of 840 K, thickness of the oxide scale formed after 1000 hours did not exceed 100-150 nm, while at the temperature of 1120 K it was roughly 5 µm thick. Furthermore, internal oxidation occurred and was the most prominent at the interphase boundaries of γ/γ’ phases and grain boundaries of γ/γ phase. Phase composition of the oxide scale changed upon applied temperature. Different combinations of MO2, M2O3 and M3O4 oxides were observed at different temperatures.