@article{schoell_kabel_lam_sharma_michler_hosemann_kaoumi_2022, title={Corrosion behavior of a series of combinatorial physical vapor deposition coatings on SiC in a simulated boiling water reactor environment}, volume={572}, ISSN={["1873-4820"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85138461418&partnerID=MN8TOARS}, DOI={10.1016/j.jnucmat.2022.154022}, abstractNote={The simulated boiling water condition corrosion properties of multilayer and combinatorial physical vapor deposition metal coatings (Zr, Cr, and/or Ti) deposited on a SiCf-SiC composite were investigated. Various compositions within the ternary system were corroded to the most suitable composition preventing underlying SiCf-SiC from further attack. Mass measurements and visual observations were conducted to identify which coatings formed protective oxides and which coatings spalled. Transmission electron microscopy was conducted to observe the microstructure of the physical vapor deposition metal layer before and after corrosion as well as identify the oxide which were forming.}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Schoell, Ryan and Kabel, Joey and Lam, Sebastian and Sharma, Amit and Michler, Johann and Hosemann, Peter and Kaoumi, Djamel}, year={2022}, month={Dec} }
 @article{schoell_xi_west_hosemann_park_kenesei_almer_shayer_kaoumi_2022, title={Investigation of the fatigue crack behavior of 304 stainless steels using synchrotron X-ray tomography and diffraction: Influence of the martensite fraction and role of inclusions}, volume={188}, ISSN={["1873-4189"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85129349891&partnerID=MN8TOARS}, DOI={10.1016/j.matchar.2022.111903}, abstractNote={The effect of fatigue on the microstructure of four-point bend specimens of three variations of 304 stainless steels (Commercial 304, 304H, and 304 L) was investigated using synchrotron x-ray tomography and diffraction. X-ray tomography revealed the formation of the fatigue-induced microvoids and crack while the diffraction data was used to quantify the amount of deformation-induced martensite found after fatigue in all samples. Transmission electron microscopy evidenced the role of the precipitates/inclusions on the microvoid formation. It was found to depend on their chemical nature. The shape of the precipitates/inclusions was also found to have an effect on the microvoid shape.}, journal={MATERIALS CHARACTERIZATION}, author={Schoell, Ryan and Xi, Li and West, Harvey and Hosemann, Peter and Park, Jun-Sang and Kenesei, Peter and Almer, Jonathan and Shayer, Zeev and Kaoumi, Djamel}, year={2022}, month={Jun} }
 @article{horn_rock_kaoumi_anderson_white_prost_rieken_saptarshi_schoell_dejong_et al._2022, title={Laser powder bed fusion additive manufacturing of oxide dispersion strengthened steel using gas atomized reaction synthesis powder}, volume={216}, ISSN={["1873-4197"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85127141491&partnerID=MN8TOARS}, DOI={10.1016/j.matdes.2022.110574}, abstractNote={Mechanically alloyed Fe-based alloys with oxide dispersion strengthening have largely dropped out of the marketplace due to high cost related to problems with complex and unreliable processing. Nevertheless, the desirable properties of oxide dispersion strengthened (ODS) steels have motivated research on alternate processing routes aimed at improving processing simplicity and reliability. Powders produced by gas atomization reaction synthesis (GARS) consist of stable Fe-Y intermetallic phases and a Cr surface oxide layer that acts as a chemical reservoir during solid-state processing and heat treatment to form a high density of nano-scale oxides. This research explores the use of Fe GARS powders, with 15 wt% Cr with micro-alloyed additions of 0.15 wt% Y and 0.10% Ti, in laser powder bed fusion (LPBF) additive manufacturing (AM), and evaluates the effectiveness of oxide dispersoid formation in the liquid melt pool. Additional oxygen was introduced by varying the LPBF chamber atmospheres using Ar, Ar + 1 wt% O, Ar + 5 wt% O, and air. Characterization of LPBF consolidated solids demonstrated the formation of a high density of nano-scale Y-Ti oxides in the build microstructures from the GARS precursor powders.}, journal={MATERIALS & DESIGN}, author={Horn, Timothy and Rock, Christopher and Kaoumi, Djamel and Anderson, Iver and White, Emma and Prost, Tim and Rieken, Joel and Saptarshi, Sourabh and Schoell, Ryan and DeJong, Matt and et al.}, year={2022}, month={Apr} }
 @article{schoell_xi_zhao_wu_hong_yu_kenesei_almer_shayer_kaoumi_2022, title={Mechanism of chlorine-induced stress corrosion cracking of two 304 SS heats in simulated marine environment through in situ X-ray tomography and diffraction: Role of deformation induced martensite and crack branching}, volume={190}, ISSN={["1873-4189"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85132337921&partnerID=MN8TOARS}, DOI={10.1016/j.matchar.2022.112020}, abstractNote={In-situ synchrotron x-ray tomography and diffraction experiments were conducted on two heats of 304SS undergoing chlorine-induced stress-corrosion-cracking (CISCC) in a simulated marine environment. The role of deformation induced martensite on CISCC was investigated through diffraction analysis where no significant amount of martensite was found to form during CISCC, indicating that it may not play a significant role in affecting the process. Tomography combined with stress-intensity analysis revealed the influence of stress-intensity on branching types with single crack growth, micro-branching, and macro-branching. Post experimental electron microscopy characterization revealed the presence of FeCl2, CrCl2, and NiCl2·6H2O compounds at the crack, which infers a dissolution mechanism during the experiment. A dissolution mechanism highlighting the synergy between stress and corrosion was proposed to explain chlorine-induced stress-corrosion-cracking and crack branching.}, journal={MATERIALS CHARACTERIZATION}, author={Schoell, Ryan and Xi, Li and Zhao, Yuchen and Wu, Xin and Hong, Yu and Yu, Zhenzhen and Kenesei, Peter and Almer, Jonathan and Shayer, Zeev and Kaoumi, Djamel}, year={2022}, month={Aug} }
 @article{jublot-leclerc_owusu-mensah_borodin_ribis_largeau_schoell_kaoumi_descoins_mangelinck_gentils_2022, title={Synthesis of Nano-Oxide Precipitates by Implantation of Ti, Y and O Ions in Fe-10%Cr: Towards an Understanding of Precipitation in Oxide Dispersion-Strengthened (ODS) Steels}, volume={15}, ISSN={["1996-1944"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85137262989&partnerID=MN8TOARS}, DOI={10.3390/ma15144857}, abstractNote={The properties of oxide dispersion-strengthened steels are highly dependent on the nature and size distribution of their constituting nano-oxide precipitates. A fine control of the processes of synthesis would enable the optimization of pertinent properties for use in various energy systems. This control, however, requires knowledge of the precise mechanisms of nucleation and growth of the nanoprecipitates, which are still a matter of debate. In the present study, nano-oxide precipitates were produced via the implantation of Y, Ti, and O ions in two different sequential orders in an Fe-10%Cr matrix that was subsequently thermally annealed. The results show that the oxides that precipitate are not necessarily favoured thermodynamically, but rather result from complex kinetics aspects related to the interaction between the implanted elements and induced defects. When Y is implanted first, the formation of nanoprecipitates with characteristics similar to those in conventionally produced ODS steels, especially with a core/shell structure, is evidenced. In contrast, when implantation starts with Ti, the precipitation of yttria during subsequent high-temperature annealing is totally suppressed, and corundum Cr2O3 precipitates instead. Moreover, the systematic involvement of {110} matrix planes in orientation relationships with the precipitates, independently of the precipitate nature, suggests matrix restriction effects on the early stages of precipitation.}, number={14}, journal={MATERIALS}, author={Jublot-Leclerc, Stephanie and Owusu-Mensah, Martin and Borodin, Vladimir A. and Ribis, Joel and Largeau, Ludovic and Schoell, Ryan and Kaoumi, Djamel and Descoins, Marion and Mangelinck, Dominique and Gentils, Aurelie}, year={2022}, month={Jul} }
 @article{zhao_schoell_zheng_cinbiz_frost_an_kaoumi_2021, title={Creep properties of advanced austenitic steel 709 determined through short experiments under in-situ neutron diffraction followed by TEM characterization}, volume={182}, ISSN={["1873-4189"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85118186981&partnerID=MN8TOARS}, DOI={10.1016/j.matchar.2021.111519}, abstractNote={In this study, the creep mechanisms at play in Alloy 709 (Fe-20Cr-25Ni) are investigated by performing short-term creep-type tests under in-situ neutron diffraction experiments. Short tests are performed in the temperature range of 500 to 900 °C under constant load with a load ranging from 50 to 150 MPa. The creep exponent and activation energy are determined using the Bird-Mukherjee-Dorn relation and compared to that obtained from conventional longer creep tests from the literature. Scanning transmission electron microscopy (S/TEM) of the post-creep microstructure indicates that interaction of dislocations with precipitates are a dominant mechanism at play. Furthermore, local elemental mapping indicated chemical segregation at grain boundaries and formation of complex precipitates.}, journal={MATERIALS CHARACTERIZATION}, author={Zhao, Yuchen and Schoell, Ryan and Zheng, Ce and Cinbiz, Mahmut N. and Frost, Matthew and An, Ke and Kaoumi, Djamel}, year={2021}, month={Dec} }
 @article{qiu_macdonald_schoell_han_mastromarino_scully_kaoumi_hosemann_2021, title={Electrochemical study of the dissolution of oxide films grown on type 316L stainless steel in molten fluoride salt}, volume={186}, ISSN={["1879-0496"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85104668265&partnerID=MN8TOARS}, DOI={10.1016/j.corsci.2021.109457}, abstractNote={The corrosion behavior of oxide films grown on Type 316L stainless steel (SS) in molten FLiNaK (LiF-NaF-KF: 46.5−11.5−42 mol.%) salt was investigated. The results show that the oxide film formed on Type 316L SS is unstable and can only temporarily protect materials from corrosion in molten FLiNaK salt. Based on the electrochemical impedance spectroscopy, the oxide dissolution rate is calculated to be 0.85 nm/h at 700 °C in molten FLiNaK salt. After the oxide film dissolved, Cr and Fe are selective dealloyed from the steel, leading to intergranular corrosion of Type 316L SS in molten fluoride salt.}, journal={CORROSION SCIENCE}, author={Qiu, Jie and Macdonald, Digby D. and Schoell, Ryan and Han, Junsoo and Mastromarino, Sara and Scully, John R. and Kaoumi, Djamel and Hosemann, Peter}, year={2021}, month={Jul} }
 @article{remillieux_kaoumi_ohara_geesey_xi_schoell_bryan_enos_summa_ulrich_et al._2020, title={Detecting and imaging stress corrosion cracking in stainless steel, with application to inspecting storage canisters for spent nuclear fuel}, volume={109}, ISSN={["1879-1174"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85074748303&partnerID=MN8TOARS}, DOI={10.1016/j.ndteint.2019.102180}, abstractNote={One of the primary concerns with the long-term performance of storage systems for spent nuclear fuel (SNF) is the potential for corrosion due to deliquescence of salts deposited as aerosols on the surface of the canister, which is typically made of austentic stainless steel. In regions of high residual weld stresses, this may lead to localized stress-corrosion cracking (SCC). The ability to detect and image SCC at an early stage (long before the cracks are susceptible to propagate through the thickness of the canister wall and leaks of radioactive material may occur) is essential to the performance evaluation and licensing process of the storage systems. In this paper, we explore a number of nondestructive testing techniques to detect and image SCC in austenitic stainless steel. Our attention is focused on a small rectangular sample of 1 × 2 in2 with two cracks of mm-scale sizes. The techniques explored in this paper include nonlinear resonant ultrasound spectroscopy (NRUS) for detection, Linear Elastodynamic Gradient Imaging Technique (LEGIT), ultrasonic C-scan, vibrothermography, and synchrotron X-ray diffraction for imaging. Results obtained from these techniques are compared. Cracks of mm-scale sizes can be detected and imaged with all the techniques explored in this study.}, journal={NDT & E INTERNATIONAL}, author={Remillieux, Marcel C. and Kaoumi, Djamel and Ohara, Yoshikazu and Geesey, Marcie A. Stuber and Xi, Li and Schoell, Ryan and Bryan, Charles R. and Enos, David G. and Summa, Deborah A. and Ulrich, T. J. and et al.}, year={2020}, month={Jan} }
 @article{qiu_han_schoell_popovic_ghanbari_kaoumi_scully_macdonald_hosemann_2020, title={Electrical properties of thermal oxide scales on pure iron in liquid lead-bismuth eutectic}, volume={176}, ISSN={["1879-0496"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85092125613&partnerID=MN8TOARS}, DOI={10.1016/j.corsci.2020.109052}, abstractNote={The impedance behavior of pre-oxidized iron in liquid lead-bismuth eutectic (LBE) at 200 °C is studied using electrochemical impedance spectroscopy. The structures and resistance of oxide grown on iron oxidized in air at different temperatures and durations are compared. The results show that the resistance of the oxide film increases with increasing oxidizing temperature, due to the formation of a thicker scale and fewer defects. At the same temperature (600 °C), increasing the oxidation time can also reduce the defect concentration in the oxide film and improve the impedance of the oxide scale in LBE.}, journal={CORROSION SCIENCE}, author={Qiu, Jie and Han, Junsoo and Schoell, Ryan and Popovic, Miroslav and Ghanbari, Elmira and Kaoumi, Djamel and Scully, John R. and Macdonald, Digby D. and Hosemann, Peter}, year={2020}, month={Nov} }
 @article{schoell_frazer_zheng_hosemann_kaoumi_2020, title={In Situ Micropillar Compression Tests of 304 Stainless Steels After Ion Irradiation and Helium Implantation}, volume={72}, ISSN={["1543-1851"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85082954591&partnerID=MN8TOARS}, DOI={10.1007/s11837-020-04127-2}, number={7}, journal={JOM}, author={Schoell, Ryan and Frazer, David and Zheng, Ce and Hosemann, Peter and Kaoumi, Djamel}, year={2020}, month={Jul}, pages={2778–2785} }
 @article{schoell_xi_zhao_wu_yu_kenesei_almer_shayer_kaoumi_2020, title={In situ synchrotron X-ray tomography of 304 stainless steels undergoing chlorine-induced stress corrosion cracking}, volume={170}, ISSN={["1879-0496"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85083895132&partnerID=MN8TOARS}, DOI={10.1016/j.corsci.2020.108687}, abstractNote={To understand the mechanisms behind chlorine-induced stress corrosion cracking (CISCC) in 304 stainless steel, synchrotron high energy x-rays were used to perform in-situ x-ray microtomography on a pre-cracked sample under load in a corrosive simulated marine environment. The tomography scans showed the crack morphology evolving into a branching crack around the surface of the sample. Finite element analysis and stress intensity analysis are conducted to explain the observed crack branching.}, journal={CORROSION SCIENCE}, author={Schoell, Ryan and Xi, Li and Zhao, Yuchen and Wu, Xin and Yu, Zhenzhen and Kenesei, Peter and Almer, Jonathan and Shayer, Zeev and Kaoumi, Djamel}, year={2020}, month={Jul} }
 @article{marsh_schoell_kaoumi_2019, title={Environmental effect on mechanical properties of a gamma-prime strengthened nickel-based alloy: Effect of the surface oxidation and formation of gamma-prime free zones}, volume={752}, ISSN={["1873-4936"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85062646666&partnerID=MN8TOARS}, DOI={10.1016/j.msea.2019.03.013}, abstractNote={The mechanical behavior of X-750 in rough vacuum environment was explored and compared with the mechanical behavior in air at a large range of temperatures (from room temperature to 900°C) for both Heat-Treated and Non-Heat-Treated X750 alloy. In the intermediate range of temperatures where the Portevin Le Chatelier (PLC) effect is observed, the effect of testing in air versus rough vacuum did not yield statistically significant different PLC characteristics. At temperatures above 650°C for Heat Treated and 750°C for Non-Heat-Treated X-750, the samples tested under rough vacuum had higher yield stress values than the respective samples tested under air. The decrease in yield stress under air was attributed to an oxide scale induced surface softening effect and the loss of strengthening efficiency for the gamma prime precipitates. At higher temperatures in air, around 800°-900°C, sinusoidal stress serrations in the stress strain curves indicated the occurrence of dynamic recrystallization (DRX). The vacuum environment however removed all stress serrations attributed to DRX, indicating that the surface oxidation with the concomitant formation of a γ’ free zone underneath the oxide layer plays a role in the DRX presence.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Marsh, Christopher and Schoell, Ryan and Kaoumi, Djamel}, year={2019}, month={Apr}, pages={136–144} }
 @article{zheng_schoell_hosemann_kaoumi_2019, title={Ion irradiation effects on commercial PH 13-8 Mo maraging steel Corrax}, volume={514}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85058006280&partnerID=MN8TOARS}, DOI={10.1016/j.jnucmat.2018.11.041}, abstractNote={The effects of irradiation on the precipitation behavior of commercial PH 13-8 Mo maraging steel a.k.a. Corrax are investigated through in-situ ion irradiation. Samples of the alloy in its solution annealed state are irradiated up to 10 dpa at 573 and 773 K using 1 MeV Kr ions, in-situ in a transmission electron microscope in order to probe irradiation effects on the precipitation usually observed in this alloy under thermal aging. Indeed, the alloy is known to develop a relatively fine distribution of precipitates during thermal aging which gives the martensitic alloy its strength. The effects of irradiation are substantiated by comparing with the same material thermally aged at 773 and 873 K for similar amounts of experimental time. Both radiation and thermal aging induced segregation and precipitation are characterized using analytical transmission electron microscopy (TEM) techniques. The diffusion coefficients under irradiation are estimated using the point defect balance equations based on Rate Theory and then compared with the thermal diffusion coefficients, demonstrating the accelerated precipitation of β-phase and Laves-phase in the irradiation case at relatively lower temperature is attributed to the radiation-enhanced diffusion. In addition, a numerical model based on classical precipitate nucleation and growth theories is introduced and shows a relatively good agreement with the experimental results in terms of precipitate density. This study serves to generate baseline data on ion irradiation effects on Corrax to learn how this steel responds to irradiation.}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Zheng, Ce and Schoell, Ryan and Hosemann, Peter and Kaoumi, Djamel}, year={2019}, pages={255–265} }