Janelle Wharry

Profile Information

Name: Professor Janelle Wharry
Institution: University of Illinois
Position: Professor
h-Index
ORCID: 0000-0001-7791-4394
Expertise: APT, Austenitic, Characterization, Cladding, Ion-Irradiation, Iron Based Alloy, Martensite Steel, Mechanical Properties, Nanoindentation, Nickel Alloys, Oxide Dispersion-Strengthened Alloy (ODS), Phase Stability, Picoindenter, Radiation Damage, Radiation Induced Segregation, SEM, Stainless Steel

Publications:

		"A data science approach for analysis and reconstruction of spinodal-like composition fields in irradiated FeCrAl alloys" Janelle Wharry, Yash Pachaury, Tomohisa Kumagai, Anter EL-AZAB, Acta Materialia Vol. 234 2022 118019 Link
		"A review of the irradiation evolution of dispersed oxide nanoparticles in the b.c.c. Fe-Cr system: Current understanding and future directions" Janelle Wharry, Matthew Swenson, Kayla Yano, Journal of Nuclear Materials Vol. 486 2017 11-20 Link
		"Application of STEM characterization for investigating radiation effects in BCC Fe-based alloys" Chad Parish, Kevin Field, Alicia Certain, Janelle Wharry, Journal of Materials Research Vol. 30 2015 1275-1289 Link This paper provides an overview of advanced scanning transmission electron microscopy (STEM) techniques used for characterization of irradiated BCC Fe-based alloys. Advanced STEM methods provide the high-resolution imaging and chemical analysis necessary to understand the irradiation response of BCC Fe-based alloys. The use of STEM with energy dispersive x-ray spectroscopy (EDX) for measurement of radiation-induced segregation (RIS) is described, with an illustrated example of RIS in proton- and self-ion irradiated T91. Aberration-corrected STEM-EDX for nanocluster/nanoparticle imaging and chemical analysis is also discussed, and examples are provided from ion-irradiated oxide dispersion strengthened (ODS) alloys. Finally, STEM techniques for void, cavity, and dislocation loop imaging are described, with examples from various BCC Fe-based alloys.
		"Characterization of microstructure and property evolution in advanced cladding and duct: Materials exposed to high dose and elevated temperature" Todd Allen, Zhijie Jiao, Djamel Kaoumi, Janelle Wharry, cem topbasi, Aaron Kohnert, Leland Barnard, Alicia Certain, Kevin Field, Gary Was, Dane Morgan, Arthur Motta, Brian Wirth, Yong Yang, Journal of Materials Research Vol. 30 2015 1246-1274 Link Designing materials for performance in high-radiation fields can be accelerated through a carefully chosen combination of advanced multiscale modeling paired with appropriate experimental validation. The studies reported in this work, the combined efforts of six universities working together as the Consortium on Cladding and Structural Materials, use that approach to focus on improving the scientific basis for the response of ferritic–martensitic steels to irradiation. A combination of modern modeling techniques with controlled experimentation has specifically focused on improving the understanding of radiation-induced segregation, precipitate formation and growth under radiation, the stability of oxide nanoclusters, and the development of dislocation networks under radiation. Experimental studies use both model and commercial alloys, irradiated with both ion beams and neutrons. Transmission electron microscopy and atom probe are combined with both first-principles and rate theory approaches to advance the understanding of ferritic–martensitic steels.
		"Collected data set size considerations for atom probe cluster analysis" Janelle Wharry, Matthew Swenson, Microscopy & Microanalysis Vol. 22 2016 690 Link
		"Comparative Thermal Aging Effects on PM-HIP and Forged Inconel 690" Keyou Mao, David Gandy, Janelle Wharry, JOM Vol. 70 2018 2218-2223 Link
		"Comparing structure-property evolution for PM-HIP and forged Alloy 625 irradiated with neutrons to 1 " Janelle Wharry, Caleb Clement, Sri Sowmya Panuganti, Patrick Warren, Yangyang Zhao, Yu Lu, Katelyn (Wheeler) Baird, David Frazer, Donna Guillen, David Gandy, Materials Science & Engineering A Vol. 857 2022 144058 Link
		"Comparing structure-property evolution for PM-HIP and forged alloy 625 irradiated with neutrons to 1 dpa" Caleb Clement, Caleb Clement, Yangyang Zhao, Yu Lu, David Frazer, Donna Guillen, David Gandy, Janelle Wharry, Materials Science and Engineering: A Vol. 857 [unknown] Link The nuclear power industry has growing interest in qualifying powder metallurgy with hot isostatic pressing (PM-HIP) to replace traditional alloy fabrication methods for reactor structural components. But there is little known about the response of PM-HIP alloys to reactor conditions. This study directly compares the response of PM-HIP to forged Ni-base Alloy 625 under neutron irradiation doses ∼0.5–1 displacements per atom (dpa) at temperatures ranging ∼321–385 °C. Post-irradiation examination involves microstructure characterization, ASTM E8 uniaxial tensile testing, and fractography. Up through 1 dpa, PM-HIP Alloy 625 appears more resistant to irradiation-induced cavity nucleation than its forged counterpart, and consequently experiences significantly less hardening. This observed difference in performance can be explained by the higher initial dislocation density of the forged material, which represents an interstitial-biased sink that leaves a vacancy supersaturation to nucleate cavities. These findings show promise for qualification of PM-HIP Alloy 625 for nuclear applications, although higher dose studies are needed to assess the steady-state irradiated microstructure.
		"Comparison of ion irradiation effects in PM-HIP and forged alloy 625" Caleb Clement, Yangyang Zhao, Patrick Warren, Xiang Liu, Sichuang Xue, David Gandy, Janelle Wharry, Journal of Nuclear Materials Vol. 558 2022 Link
		"Comparison of ion irradiation effects in PM-HIP and forged alloy 625" Caleb Clement, Patrick Warren, Yangyang Zhao, Xiang Liu, David Gandy, Janelle Wharry, Sichuang Xue, Journal of Nuclear Materials Vol. 558 [unknown] Link The nuclear industry has growing interest in replacing forgings with structural components fabricated by powder metallurgy with hot isostatic pressing (PM-HIP), owing to their chemical homogeneity, uniform grain structure, and near-net shape production. This study compares the ion irradiation response of PM-HIP and forged Alloy 625, over 50 and 100 dpa, 400 °C and 500 °C. Microstructure is characterized using down-zone bright-field scanning transmission electron microscopy (DZBFSTEM), and hardening is characterized using nanoindentation. PM-HIP Alloy 625 has a lower initial dislocation line density, resulting in a more rapid onset of dislocation loop growth and unfaulting than the forged material. But the total defect population (i.e. loop line length plus dislocation density) is insensitive to fabrication method. This finding shows promise for the eventual qualification of PM-HIP alloys for nuclear applications.
		"Comparison of PM-HIP to forged SA508 pressure vessel steel under high-dose neutron irradiation" Janelle Wharry, Wen Jiang, Yangyang Zhao, Yu Lu, David Frazer, Donna Guillen, David Gandy, Journal of Nuclear Materials Vol. 594 2024 155018 Link
		"Correlation between the microstructure and mechanical properties of irradiated Fe-9Cr ODS" Corey Dolph, Matthew Swenson, Janelle Wharry, Transactions of the American Nuclear Society Vol. 110 2014 421-424 Link
		"Deformation-assisted rejuvenation of irradiation-induced phase instabilities in Cu-Ta heterophase nanocomposite" Janelle Wharry, Priyam Patki, Yaqiao Wu, B. Chad Hornbuckle, Kristopher Darling, JOM Vol. 74 2022 4094-4106 Link
		"Effect of laser welding on deformation mechanisms in irradiated austenitic stainless steel" Janelle Wharry, Keyou Mao, Cheng Sun, Xiang Liu, Haozheng Qu, Aaron French, Paula Freyer, Frank Garner, Lin Shao, Journal of Nuclear Materials Vol. 528 2020 151878 Link Deformation mechanism of a laser weld on neutron irradiated AISI 304L stainless steel was studied by in-situ microcompression test at room temperature. The deformation-induced austenite-to-martensite phase transformation occurs in {101}-oriented grains in the irradiated base metal, while deformation twinning prevails in {101}-oriented grains in the weld heat affected zone (HAZ). A high number density of irradiation-induced voids in the base metal provides sufficient nucleation sites for the austenite-to-martensite phase transformation under compression at room temperature. A deformation map is established to predict critical twinning stress for face-centered-cubic (fcc) metals and alloys. Our results show that irradiation-induced voids can tailor the deformation mechanisms of austenitic stainless steel.
		"Effects of corrosion-inhibiting surface treatments on irradiated microstructure development in Ni-base alloy 718" Keyou Mao, Vijay Vasudevan, Janelle Wharry, Journal of Nuclear Materials Vol. 512 2018 276-287 Link
		"Effects of corrosion-inhibiting surface treatments on irradiated microstructure development in Ni-base Alloy 718" Keyou Mao, Janelle Wharry, Vijay Vasudevan, Journal of Nuclear Materials Vol. 512 2018 276-287 Link
		"Effects of proton irradiation on microstructure and mechanical properties of nanocrystalline Cu–10at%Ta alloy" Priyam Patki, Yaqiao Wu, Janelle Wharry, Materialia Vol. 9 2020 Link
		"Elimination of remnant phases in low-temperature growth of wurtzite ScAlN by molecular-beam epitaxy" Janelle Wharry, Amrita Sen, Mukesh Bachhav, Brandon Dzuba, T. Nguyen, Rosa Diaz, Megha Dubey, Michael Manfra, Oana Malis, Journal of Applied Physics Vol. 132 2022 175701 Link
		"Experiment design for the neutron irradiation of PM-HIP alloys for nuclear reactors" Donna Guillen, Janelle Wharry, Gregory Housley, Cody Hale, Jason Brookman, David Gandy, Nuclear Engineering and Design Vol. 402 2023 Link
		"Grain Evolution in Thermally Aged Cast and Hot Isostatic Pressed Inconel 625" Elizabeth Getto, Janelle Wharry, Microscopy and Microanalysis Vol. Suppl 1 2018 666-667 Link
		"Grain orientation dependence of nanoindentation and deformation-induced martensitic phase transformation in neutron irradiated AISI 304L stainless steel" Keyou Mao, Cheng Sun, Yina Huang, Ching-Heng Shiau, Frank Garner, Paula Freyer, Janelle Wharry, Materialia Vol. 5 2019 100208 Link
		"In situ TEM mechanical testing: an emerging approach for characterization of polycrystalline, irradiated alloys" Janelle Wharry, Kayla Yano, Matthew Swenson, Yaqiao Wu, Microscopy & Microanalysis Vol. 22 2016 1478 Link
		"In situ tensile study of PM-HIP and wrought 316L stainless steel and Inconel 625 alloys with high energy diffraction microscopy" Janelle Wharry, Donna Guillen, Elizabeth Getto, Darren Pagan, Materials Science & Engineering A Vol. 738 2018 380-388 Link
		"Intrinsic-extrinsic size effect relationship for micromechanical tests" Janelle Wharry, Kayla Yano, Priyam Patki, Scripta Materialia Vol. 162 2019 63-67 Link Miniaturized mechanical tests are commonly utilized to evaluate properties of materials, including thin films, nanostructured, and irradiated materials. However, the specimen size effect occurs when miniaturized sample geometries contain too few dislocation sources, resulting in elevated yield stresses. The size effect is controlled by extrinsic (specimen dimensions) and intrinsic (microstructure) factors. Here, we summarize extrinsic and in- trinsic size effects from micro-compression pillar, micro-cantilever bend, and flexure studies reported in the ar- chival literature. We find an approximately linear relationship between intrinsic and extrinsic size effects. Meaningful mechanical properties can be measured when extrinsic size dominates the intrinsic size.
		"Ion Implantation-Induced Plastic Phenomena in Metallic Alloys" Patrick Warren, Janelle Wharry, Caleb Clement, Yang Yang, Yongwen Sun, Jim Ciston, Colin Ophus, Journal of Materials Vol. [unknown] Link Ion implantation is widely used for doping semiconductors or electroceramic materials and probing material behaviors in extreme radiation environments. However, implanted ions can induce compressive stresses into the host material, which can induce plasticity and mesoscopic deformation. However, these phenomena have almost exclusively been observed in brittle ionic and/or covalently bonded materials. Here, we present transmission electron micro- scopy observations of unusual implantation-induced plasticity in two metallic alloys. First, Fe2+ ions induce dislocation plasticity below the implanted layer in a model Fe-P alloy. Next, He+ ions form pressurized cavities which activate the fcc-to-hcp strain-induced martensitic transformation in Alloy 625. In both cases, the plasticity can be explained by a combination of implanted ions being incorporated into the lattice and the creation of irradiation defects. These findings have significant implications for mechanical testing of ion-implanted layers, while also opening pathways distributions in metallic alloys.
		"Laser weld-induced formation of amorphous Mn-Si precipitate in 304 stainless steel" Janelle Wharry, Keyou Mao, Yaqiao Wu, Cheng Sun, Emmanuel Perez, Materialia Vol. 3 2018 174-177 Link
		"Materials qualification through the Nuclear Science User Facilities (NSUF): A case study on irradiated PM-HIP structural alloys" Janelle Wharry, Donna Guillen, Caleb Clement, Saquib Bin Habib, Wen Jiang, Yu Lu, Yaqiao Wu, Ching-Heng Shiau, David Frazer, Brenden Heidrich, Collin Knight, David Gandy, Frontiers in Nuclear Engineering Vol. 2 2023 1306529 Link
		"Mechanical testing data from neutron irradiations of PM-HIP and conventionally manufactured nuclear structural alloys" Donna Guillen, Janelle Wharry, Caleb Clement, Yangyang Zhao, Katelyn Wachs, David Frazer, Jatuporn Burns, Yu Lu, Yaqiao Wu, Collin Knight, David Gandy, Data in Brief Vol. 48 2023 109092 Link This article presents the comprehensive mechanical testing data archive from a neutron irradiation campaign of nuclear structural alloys fabricated by powder metallurgy with hot isostatic pressing (PM-HIP). The irradiation campaign was designed to facilitate a direct comparison of PM-HIP to conventional casting or forging. Five common nuclear structural alloys were included in the campaign: 316L stainless steel, SA508 pressure vessel steel, Grade 91 ferritic steel, and Ni-base alloys 625 and 690. Irradiations were carried out in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) to target doses of 1 and 3 displacements per atom (dpa) at target temperatures of 300 and 400 °C. This article contains the data collected from post-irradiation uniaxial tensile tests following ASTM E8 specifications, fractography of these tensile bars, and nanoindentation. By making this systematic and valuable neutron irradiated mechanical behavior dataset openly available to the nuclear materials research community, researchers may now use this data to populate material performance databases, validate material performance and hardening models, design follow-on experiments, and enable future nuclear code-qualification of PM-HIP techniques.
		"Mechanisms of ion irradiation induced ordering in amorphous TiO2 nanotubes: Effects of ion mass and energy" Janelle Wharry, Tristan Olsen, Wei-Ying Chen, Miu-Lun Lau, Cyrus Koroni, Sarah Pooley, Chao Yang, Md Ali Muntaha, Zhongxia Shang, Dewen Hou, Ling Wang, Min Long, Hui (Claire) Xiong, Journal of Nuclear Materials Vol. 597 2024 155114 Link
		"Method for Evaluating Irradiation Effects on Flow Stress in Fe-9%Cr ODS Using TEM In Situ Cantilevers" Kayla Yano, Yaqiao Wu, Janelle Wharry, Journal of Minerals, Metals & Materials Society Vol. 72 2020 2065-2074 Link
		"Method for Fabricating Depth-Specific TEM in situ Tensile Bars" Patrick Warren, Yaqiao Wu, Janelle Wharry, George Warren, Megha Dubey, Jatu Burns, Journal of Materials Vol. 72 [unknown] 2057 - 2064 Link The growing use of ion irradiation to assess degradation of nuclear materials has created a need to develop novel methods to probe the mechanical response of shallow ion-irradiated layers. Transmission electron microscopy (TEM) in situ mechanical testing can isolate the ion-irradiated layer from its unirradiated substrate. However, there is a lack of established procedures for preparing TEM in situ mechanical testing specimens from bulk materials requiring depth-specific examination, e.g., target dose on the ion irradiation damage profile. This study demonstrates a new method for extracting depth-specific TEM in situ tensile bars from a bulk specimen of Fe-5 wt.%Mo. Measured yield stress, ultimate tensile stress, Young’s modulus, and elongation are consistent with those properties obtained from similarly sized Fe and Mo single-crystal nanowires. Results are discussed in the context of the specimen size effect.
		"Method for fabricating depth-specific TEM in situ tensile bars" Janelle Wharry, George Warren, Patrick Warren, Megha Dubey, Jatuporn Burns, Yaqiao Wu, JOM Vol. 72 2020 2057-2064 Link
		"Microstructure and microchemistry of laser welds of irradiated austenitic steels" Keyou Mao, Aaron French, Xiang Liu, Lucille Giannuzzi, Cheng Sun, Megha Dubey, Paula Freyer, Jonathan Tatman, Frank Garner, Lin Shao, Janelle Wharry, Materials and Design Vol. 206 2021 Link
		"Microstructure of laser weld repairs of irradiated austenitic steels" Janelle Wharry, Keyou Mao, Aaron French, Xiang Liu, Yaqiao Wu, Cheng Sun, Paula Freyer, Jonathan Tatman, Lucille Giannuzzi, Frank Garner, Lin Shao, Materials & Design Vol. 206 2021 109764 Link
		"Microstructure-property relationships across AISI 304/308L stainless steel laser weldments" Janelle Wharry, Keyou Mao, Vikas Tomar, Yaqiao Wu, Materials Science & Engineering A Vol. 721 2018 234-243 Link
		"Nanocluster Evolution in D9 Austenitic Steel under Neutron and Proton Irradiation" Janelle Wharry, Mukesh Bachhav, Cheng Sun, Amrita Sen, Suraj Venkateshwaran Mullurkara, Akshara Bejawada, Materials Vol. 16 2023 4852 Link Austenitic stainless steel D9 is a candidate for Generation IV nuclear reactor structural materials due to its enhanced irradiation tolerance and high-temperature creep strength compared to conventional 300-series stainless steels. But, like other austenitic steels, D9 is susceptible to irradiation- induced clustering of Ni and Si, the mechanism for which is not well understood. This study utilizes atom probe tomography (APT) to characterize the chemistry and morphology of Ni–Si nanoclusters in D9 following neutron or proton irradiation to doses ranging from 5–9 displacements per atom (dpa) and temperatures ranging from 430–683 ºC. Nanoclusters form only after neutron irradiation and exhibit classical coarsening with increasing dose and temperature. The nanoclusters have Ni3Si stoichiometry in a Ni core–Si shell structure. This core–shell structure provides insight into a potentially unique nucleation and growth mechanism—nanocluster cores may nucleate through local, spinodal-like compositional fluctuations in Ni, with subsequent growth driven by rapid Si diffusion. This study underscores how APT can shed light on an unusual irradiation-induced nanocluster nucleation mechanism active in the ubiquitous class of austenitic stainless steels.
		"Nanocluster irradiation evolution in Fe-9%Cr ODS and ferritic-martensitic alloys" Matthew Swenson, Janelle Wharry, Journal of Nuclear Materials Vol. 2017 2017 24-40 Link The objective of this study is to evaluate the influence of dose rate and cascade morphology on nanocluster evolution in a model Fe-9%Cr oxide dispersion strengthened steel and the commercial ferritic/martensitic (F/M) alloys HCM12A and HT9. We present a large, systematic data set spanning the three alloys, three irradiating particle types, four orders of magnitude in dose rate, and doses ranging 1–100 displacements per atom over 400–500 °C. Nanoclusters are characterized using atom probe tomography. ODS oxide nanoclusters experience partial dissolution after irradiation due to inverse Ostwald ripening, while F/M nanoclusters undergo Ostwald ripening. Damage cascade morphology is indicative of nanocluster number density evolution. Finally, the effects of dose rate on nanocluster morphology provide evidence for a temperature dilation theory, which purports that a negative temperature shift is necessary for higher dose rate irradiations to emulate nanocluster evolution in lower dose rate irradiations.
		"Plastic zone size for nanoindentation of irradiated Fe-9wt% Cr ODS alloy" Janelle Wharry, Corey Dolph, Douglas da Silva, Matthew Swenson, Journal of Nuclear Materials Vol. 481 2016 33-45 Link The objective of this study is to determine irradiation effects on the nanoindentation plastic zone morphology in a model Fe–9%Cr ODS alloy. Specimens are irradiated to 50 displacements per atom at 400°C with Fe++ self-ions or to 3 dpa at 500°C with neutrons. The as-received specimen is also studied as a control. The nanoindentation plastic zone size is calculated using two approaches: (1) an analytical model based on the expanding spherical cavity analogy, and (2) finite element modeling (FEM). Plastic zones in all specimen conditions extend radially outward from the indenter, ~4–5 times the tip radius, indicative of fully plastic contact. Non-negligible plastic flow in the radial direction requires the experimentalist to consider the plastic zone morphology when nanoindenting ion-irradiated specimens; a single nanoindent may sample non-uniform irradiation damage, regardless of whether the indent is made top-down or in cross-section. Finally, true stress-strain curves are generated.
		"Probing the Damage Recovery Mechanism in Irradiated Stainless Steels Using In-Situ Microcantilever Bending Test" Keyou Mao, Hao Wang, Haozheng Qu, Kayla Yano, Philip Edmondson, Cheng Sun, Janelle Wharry, Frontiers in Materials Vol. 2022 Link
		"Rate Theory Model of Irradiation-Induced Solute Clustering in b.c.c. Fe-Based Alloys" Matthew Swenson, Janelle Wharry, Journal of Nuclear Materials Vol. 72(9) 2020 Link
		"Role of cavities on deformation-induced martensitic transformation pathways in a laser-welded, neutron irradiated austenitic stainless steel" Janelle Wharry, Keyou Mao, Cheng Sun, Ching-Heng Shiau, Kayla Yano, Paula Freyer, Anter EL-AZAB, Frank Garner, Aaron French, Lin Shao, Scripta Materialia Vol. 178 2020 1-6 Link The role of cavities on deformation-induced martensitic phase transformations is studied in a laser-welded and neutron irradiated austenitic stainless steel. Orientation dependent nanoindentation experiments are performed in the base metal and the weld heat affected zone (HAZ) at room temperature. Transmission electron microscopy study of deformed microstructures indicates indentation-induced α’-martensite forms in the base metal, whereas α’- and ε-martensite arise in the HAZ. The different pathway of martensite phase transformation is attributed to the laser weld-induced annealing of cavities. Our results suggest that deformation-induced martensitic phase transformation of austenitic stainless steel is correlated to neutron irradiated cavity structures.
		"Systematic study of radiation-induced segregation in neutron-irradiated FeCrAl alloys" Janelle Wharry, Priyam Patki, Dalong Zhang, Kevin Field, Journal of Nuclear Materials Vol. 574 2023 154205 Link
		"TEM characterization of irradiated microstructure of Fe-9%Cr ODS and ferritic-martensitic alloys" Matthew Swenson, Janelle Wharry, Journal of Nuclear Materials Vol. 502 2018 30-41 Link The objective of this study is to evaluate the effects of irradiation dose and dose rate on defect cluster (i.e. dislocation loops and voids) evolution in a model Fe-9%Cr oxide dispersion strengthened steel and commercial ferritic-martensitic steels HCM12A and HT9. Complimentary irradiations using Fe2+ ions, protons, or neutrons to doses ranging from 1 to 100 displacements per atom (dpa) at 500?°C are conducted on each alloy. The irradiated microstructures are characterized using transmission electron microscopy (TEM). Dislocation loops exhibit limited growth after 1 dpa upon Fe2+ and proton irradiation, while any voids observed are small and sparse. The average size and number density of loops are statistically invariant between Fe2+, proton, and neutron irradiated specimens at otherwise fixed irradiation conditions of ~3 dpa, 500?°C. Therefore, we conclude that higher dose rate charged particle irradiations can reproduce the neutron irradiated loop microstructure with temperature shift governed by the invariance theory; this temperature shift is ~0?°C for the high sink strength alloys studied herein.
		"TEM in situ cube-corner indentation analysis using ViBe motion detection algorithm" Matthew Swenson, Janelle Wharry, Kayla Yano, Stephen Thomas, Yang Lu, Journal of Nuclear Materials Vol. 502 2018 201-212 Link Transmission electron microscopic (TEM) in situ mechanical testing is a promising method for understanding plasticity in shallow ion irradiated layers and other volume-limited materials. One of the simplest TEM in situ experiments is cube-corner indentation of a lamella, but the subsequent analysis and interpretation of the experiment is challenging, especially in engineering materials with complex microstructures. In this work, we: (a) develop MicroViBE, a motion detection and background subtraction-based post-processing approach, and (b) demonstrate the ability of MicroViBe, in combination with post-mortem TEM imaging, to carry out an unbiased qualitative interpretation of TEM indentation videos. We focus this work around a Fe-9%Cr oxide dispersion strengthened (ODS) alloy, irradiated with Fe2+ ions to 3 dpa at 500?°C. MicroViBe identifies changes in Laue contrast that are induced by the indentation; these changes accumulate throughout the mechanical loading to generate a “heatmap” of features in the original TEM video that change the most during the loading. Dislocation loops with b?=?½ <111> identified by post-mortem scanning TEM (STEM) imaging correspond to hotspots on the heatmap, whereas positions of dislocation loops with b?=?<100> do not correspond to hotspots. Further, MicroViBe enables consistent, objective quantitative approximation of the b?=?½ <111> dislocation loop number density.
		"TEM in situ micropillar compression tests of ion irradiated oxide dispersion strengthened alloy" Matthew Swenson, Janelle Wharry, Yaqiao Wu, Kayla Yano, Journal of Nuclear Materials Vol. 483 2016 107 Link The growing role of charged particle irradiation in the evaluation of nuclear reactor candidate materials requires the development of novel methods to assess mechanical properties in near-surface irradiation damage layers just a few micrometers thick. In situ transmission electron microscopic (TEM) mechanical testing is one such promising method. In this work, microcompression pillars are fabricated from a Fe2+ ion irradiated bulk specimen of a model Fe-9%Cr oxide dispersion strengthened (ODS) alloy. Yield strengths measured directly from TEM in situ compression tests are within expected values, and are consistent with predictions based on the irradiated microstructure. Measured elastic modulus values, once adjusted for the amount of deformation and deflection in the base material, are also within the expected range. A pillar size effect is only observed in samples with minimum dimension =100 nm due to the low inter-obstacle spacing in the as received and irradiated material. TEM in situ micropillar compression tests hold great promise for quantitatively determining mechanical properties of shallow ion-irradiated layers.
		"The comparison of microstructure and nanocluster evolution in proton and neutron irradiated Fe?9%Cr ODS steel to 3 dpa at 500 °C" Janelle Wharry, Matthew Swenson, Journal of Nuclear Materials Vol. 467 2015 97-112 Link A model Fe–9%Cr oxide dispersion strengthened (ODS) steel was irradiated with protons or neutrons to a dose of 3 displacements per atom (dpa) at a temperature of 500 °C, enabling a direct comparison of ion to neutron irradiation effects at otherwise fixed irradiation conditions. The irradiated microstructures were characterized using transmission electron microscopy and atom probe tomography including cluster analysis. Both proton and neutron irradiations produced a comparable void and dislocation loop microstructure. However, the irradiation response of the Ti–Y–O oxide nanoclusters varied. Oxides remained stable under proton irradiation, but exhibited dissolution and an increase in Y:Ti composition ratio under neutron irradiation. Both proton and neutron irradiation also induced varying extents of Si, Ni, and Mn clustering at existing oxide nanoclusters. Protons are able to reproduce the void and loop microstructure of neutron irradiation carried out to the same dose and temperature. However, since nanocluster evolution is controlled by both diffusion and ballistic impacts, protons are rendered unable to reproduce the nanocluster evolution of neutron irradiation at the same dose and temperature.
		"The effects of oxide evolution on mechanical properties in proton- and neutron-irradiated Fe-9%Cr ODS steel" Matthew Swenson, Corey Dolph, Janelle Wharry, Journal of Nuclear Materials Vol. 479 2016 426-435 Link The objective of this study is to evaluate the effect of irradiation on the strengthening mechanisms of a model Fe-9%Cr oxide dispersion strengthened steel. The alloy was irradiated with protons or neutrons to a dose of 3 displacements per atoms at 500 °C. Nanoindentation was used to measure strengthening due to irradiation, with neutron irradiation causing a greater increase in yield strength than proton irradiation. The irradiated microstructures were characterized using transmission electron microscopy and atom probe tomography (APT). Cluster analysis reveals solute migration from the Y-Ti-O-rich nanoclusters to the surrounding matrix after both irradiations, though the effect is more pronounced in the neutron-irradiated specimen. Because the dissolved oxygen atoms occupy interstitial sites in the iron matrix, they contribute significantly to solid solution strengthening. The dispersed barrier hardening model relates microstructure evolution to the change in yield strength, but is only accurate if solid solution contributions to strengthening are considered simultaneously.
		"The role of Cr, P, and N solutes on the irradiated microstructure of bcc Fe" Janelle Wharry, Patrick Warren, Caleb Clement, Amrita Sen, Chao Yang, Wei-Ying Chen, Yaqiao Wu, Ling Wang, Journal of Nuclear Materials Vol. 583 2023 154531 Link
		"The role of irradiation on deformation-induced martensitic phase transformations in fcc alloys" Janelle Wharry, Keyou Mao, Journal of Materials Research Vol. 35 2020 1660-1671 Link
		"Thermal Aging and the Hall–Petch Relationship of PM-HIP and Wrought Alloy 625" Janelle Wharry, Keyou Mao, David Gandy, Elizabeth Getto, JOM Vol. 71 2019 2837 Link Powder metallurgy with hot isostatic pressing (PM-HIP) is an advanced alloy processing method capable of fabricating complex nuclear reactor components near-net shape, reducing the need for machining and welding. For heat exchangers and steam generators, thermal aging of PM-HIP materials must be comparable or superior to conventional castings or forgings. This study compares thermal aging effects in PM-HIP and wrought alloy 625. Isothermal aging is carried out over 400–800°C for 100 h. Both PM-HIP and wrought materials have equiaxed grains with a uniform orientation distribution. The PM-HIP material has finer grains than the wrought material at all aging conditions. Both PM-HIP and wrought materials have a comparable hardness and modulus measured by nanoindentation. Hardness remains unchanged with aging except the wrought material aged at 800°C, which exhibits softening. Overall, PM-HIP alloy 625 responds comparably to wrought alloy 625 and is superior at 800°C. Results are used to calculate a Hall–Petch coefficient.
		"Understanding plasticity in irradiated alloys through TEM in situ compression pillar tests" Janelle Wharry, Haozheng Qu, Kayla Yano, Priyam Patki, Matthew Swenson, Journal of Materials Research Vol. 35 2020 1037-1050 Link
		"Unexpected deformation-induced martensitic phase transformations in Ni-Cr alloys and Ni-Cr-Fe alloys" Janelle Wharry, Caleb Clement, Chao Yang, Materials Science & Engineering A Vol. 892 2024 146029 Link

Presentations:

	"A New Method for TEM in situ Tensile Testing of Ion Irradiated Alloys" Patrick Warren, George Warren, Nuela Enebechi, Jatu Burns, Megha Dubey, Janelle Wharry, MiNES Conference October 6-10, (2019)
	"A predictive model for irradiation-induced nanocluster evolution in b.c.c. Fe-based alloys" Matthew Swenson, Janelle Wharry, TMS Annual Meeting 2017 [unknown]
	"A standards perspective on nano mechanical testing to accelerate nuclear materials development and qualification" Janelle Wharry, Priyam Patki, George Warren, Patrick Warren, JB Hall, TMS 2021 March 15-18, (2021)
	"Assessing mechanical properties of irradiated materials by nanomechanical testing" Janelle Wharry, Kayla Yano, Yaqiao Wu, ICSMA18 July 15-18, (2018)
	"Cluster evolution in F/M alloys upon neutron, proton, and self-ion irradiation" Matthew Swenson, Janelle Wharry, Materials Science & Technology 2016 [unknown]
	"Comparison of Ion and Neutron Irradiations to 3 dpa at 500°C in Ferritic-Martensitic Alloys" Matthew Swenson, Janelle Wharry, American Nuclear Society Annual Meeting 2016 [unknown]
	"Comparison of SXRD and Microstructure of Electron-beam Welded RPV Steels" Jasmyne Emerson, Grayson Nemets, Elliot Marrero, MEHMET TOPSAKAL, Simerjeet Gill, Janelle Wharry, Maria Okuniewski, NSLS-II, CFN, & LBMS Users’ Meeting April 24-27, (2023)
	"Correlation between irradiation defects and transition dimension for TEM in situ mechanical testing" Matthew Swenson, Janelle Wharry, Kayla Yano, American Nuclear Society 2017 Annual Meeting June 11-15, (2018)
	"Effect of residual stress mitigation surface treatment techniques on the irradiation tolerance of Ni-base alloys" Keyou Mao, Vijay Vasudevan, Janelle Wharry, FONTEVRAUD 9 September 17-20, (2018)
	"Grain evolution in thermally aged cast and hot isostatic pressed Inconel 625" Elizabeth Getto, Janelle Wharry, Poster - M&M 2018 August 5-9, (2018)
	"In Situ TEM Clamped Beam Fracture in Fe-9Cr ODS" Kayla Yano, Janelle Wharry, ANS Annual Meeting 2018 June 17-21, (2018)
	"In situ TEM fracture testing for shallow ion irradiated layers" Janelle Wharry, Kayla Yano, Microscopy & Microanalysis 2017 April 6-7, (2017)
	"In situ TEM mechanical testing approaches for ion irradiated alloys" Janelle Wharry, International Conference on Plasticity [unknown]
	"In situ TEM mechanical testing: an emerging approach for characterization of polycrystalline, irradiated alloys" Matthew Swenson, Janelle Wharry, Yaqiao Wu, Kayla Yano, Microscopy & Microanalysis July 24-28, (2016)
	"In situ TEM microcompression pillar size effects in Fe-9Cr ODS" Matthew Swenson, Janelle Wharry, Kayla Yano, American Nuclear Society June 12-16, (2016)
	"Linking RIS and Grain Decohesion Using In Situ TEM 4-point Beams" Kayla Yano, Janelle Wharry, The Minerals, Metals & Materials Society 2018 March 11-15, (2018)
	"Mechanical Martensites in Nuclear Steels" Janelle Wharry, Patrick Warren, Haozheng Qu, TMS 2023 March 19-23, (2023)
	"Mechanics of irradiated alloys studied through in situ TEM testing" Janelle Wharry, Kayla Yano, Yaqiao Wu, TMS 2018 March 11-15, (2018)
	"Method for extracting true stress from TEM in situ compression testing" Kayla Yano, Janelle Wharry, M&M 2018 August 5-9, (2018)
	"Microstructural and mechanical integrity of laser weldment of neutron irradiated AISI 304 SS" Keyou Mao, Paula Freyer, Frank Garner, Janelle Wharry, TMS 2018 March 11-15, (2018)
	"Microstructural and micromechanical characterization of laser weld repairs on neutron irradiated 304 stainless steel" Keyou Mao, Paula Freyer, Cheng Sun, Frank Garner, Janelle Wharry, NUMAT 2018 October 15-18, (2018)
	"Microstructure evolution of laser weld repairs of 304SS at high dose ion irradiation" Keyou Mao, Paula Freyer, Jonathan Tatman, Frank Gift, Frank Garner, Janelle Wharry, Poster - FONTEVRAUD 9 September 17-20, (2018)
	"Neutron Irradiation of Nuclear Structural Materials Fabricated by Powder Metallurgy with Hot Isostatic Pressing" David Gandy, Donna Guillen, Janelle Wharry, 2017 ANS Annual Meeting [unknown]
	"Qualitative Analysis of deformation in Proton Irradiated Nanocrystalline Copper Tantalum Alloy" Priyam Patki, Janelle Wharry, Yaqiao Wu, The Minerals, Metals and Materials Society March 10-14, (2019)
	"Rate theory model for irradiation evolution of nanaclusters" Janelle Wharry, Materials Research Society Fall Meeting [unknown]
	"Role of Phosphorus in Irradiated Microstructure Evolution of a Binary Fe-P Model Alloy by TEM in situ Irradiation" Patrick Warren, Wei-Ying Chen, Amrita Sen, Ling Wang, Janelle Wharry, TMS Conference February 27-3, (2022)
	"Synchrotron X-ray Diffraction Characterization of the Phase Transformation Behaviors Induced by Electron Beam Welding in SA508 Reactor Pressure Vessel Steels" Jasmyne Emerson, Grayson Nemets, Elliot Marrero, MEHMET TOPSAKAL, Simerjeet Gill, Janelle Wharry, Maria Okuniewski, Materials in Nuclear Energy Systems (MiNES 2023) December 11-14, (2023)
	"TEM in situ mechanical testing of proton irradiated nanocrystalline copper tantalum alloy" Yaqiao Wu, Janelle Wharry, TMS 2018 March 11-15, (2018)
	"Temperature shift for emulating solute cluster evolution using higher dose rate irradiation" Matthew Swenson, Janelle Wharry, TMS 2018 March 11-15, (2018)
	"The Influence of Nanoindentation Orientation on Deformation Mechanisms in Irradiated Fe-P and Fe-N" Patrick Warren, Janelle Wharry, TMS 2023 March 19-23, (2023)

NSUF Articles:

U.S. DOE Nuclear Science User Facilities Awards 30 Rapid Turnaround Experiment Research Proposals - Awards total nearly $1.2 million The U.S. Department of Energy (DOE) Nuclear Science User Facilities (NSUF) has selected 30 new Rapid Turnaround Experiment (RTE) projects, totaling up to approximately $1.2 million. These projects will continue to advance the understanding of irradiation effects in nuclear fuels and materials in support of the mission of the DOE Office of Nuclear Energy. Wednesday, April 26, 2017 - Calls and Awards
DOE Awards 33 Rapid Turnaround Experiment Research Proposals - Projects total approximately $1.5 million These projects will continue to advance the understanding of irradiation effects in nuclear fuels and materials in support of the mission of the DOE Office of Nuclear Energy. Monday, May 14, 2018 - Calls and Awards
DOE awards 39 RTE Projects - Projects total approximately $1.3 million Thursday, February 1, 2018 - Calls and Awards
RTE 2nd Call Awards Announced - Projects total approximately $1.6 million These project awards went to principal investigators from 26 U.S. universities, eight national laboratories, two British universities, and one Canadian laboratory. Tuesday, May 14, 2019 - Calls and Awards
DOE Awards 31 RTE Proposals, Opens FY-20 1st Call - Projects total $1.1 million; Next proposals due 10/31 Awards will go to 22 principal investigators from universities, six from national laboratories, and three from foreign universities. Tuesday, September 17, 2019 - Calls and Awards, Announcement
DOE-NE Awards 19 RTE Projects - New projects total approximately $690K Thursday, February 6, 2020 - Announcement, Calls and Awards, Newsletter, News Release
Users Organization Meeting Presentations Now Available - Wednesday, March 25, 2020 - Newsletter, Users Group
CINR Awards Announced - Eight projects were selected Projects will take advantage of NSUF capabilities to investigate important nuclear fuel and material applications. Thursday, June 27, 2019 - Calls and Awards
Three Consolidated Innovative Nuclear Research Proposals Awarded - Awards total approximately $6.4M Thursday, June 15, 2023 - Calls and Awards
NSUF awards 28 Rapid Turnaround Experiment proposals - Approximately $1.74M has been awarded. The new call closes June 28. Thursday, June 1, 2023 - Calls and Awards

Accomplishments

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Authored the most NSUF-supported publications

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Top 5% of all RTE Proposal submissions

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Collaborated on 3+ RTE Proposals

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Reviewed 10+ RTE Proposals

NSUF Supported Research

Assessing Deformation Mechanisms in Irradiated Superalloy 718 using Ultra-Miniature Specimens - FY 2023 RTE 2nd Call, #4674

Characterizing Si-Ni-Mn clustering in ion irradiated Fe-9Cr ODS alloy - FY 2015 RTE 2nd Call, #569

Correlating mechanical properties with microstructure evolution in irradiated F/M and ODS alloys - FY 2014 RTE 2nd Call, #485

Effects of High Dose on Laser Welded, Irradiated AISI 304SS - FY 2016 CINR, #3045

Extension and Validation of Rate Theory Model of Nanocluster Irradiation Evolution: An Atom Probe Tomography Study - FY 2018 RTE 1st Call, #1198

Influence of Grain Boundary RIS on Dislocation Mobility in Irradiated Steels - FY 2019 RTE 2nd Call, #1723

Irradiated Microstructure Evolution in Cast Compared to PM-HIP Alloy 625 - FY 2018 RTE 2nd Call, #1412

Irradiation studies on electron beam welded PM-HIP pressure vessel steel - FY 2019 CINR, #3077

Irradiation-Corrosion of Alumina-Forming Austenitic Stainless Steels in Static Lead - FY 2023 CINR, #4737

Irradiation-induced segregation, phase stability, and microstructure in 8-10 wt% Cr ODS alloys - FY 2014 RTE 2nd Call, #486

Proton Irradiations of Alloys Fabricated by Powder Metallurgy and Hot Isostatic Pressing - FY 2015 RTE 2nd Call, #558

Radiation induced segregation and phase separation in neutron irradiated FeCrAl alloys - FY 2017 RTE 2nd Call, #908

Si-Ni-Mn clustering in irradiated Fe-9Cr oxide dispersion strengthened alloy - FY 2015 RTE 1st Call, #540

Synergetic Effects of Irradiation, Temperature, and Strain on Ordering in Ni-Based Alloys - FY 2024 RTE 2nd Call, #4938

Synergistic ODS Nanocluster Irradiation Evolution and Radiation-Induced Segregation - FY 2019 RTE 3rd Call, #2885

TEM in situ microcantilever testing of irradiated F/M alloys - FY 2016 RTE 2nd Call, #656

Toward an understanding of the effect of dose rate on the irradiation response of F-M alloys - FY 2013 RTE Solicitation, #419

Unraveling the Mystery of Irradiation-Induced Void Closure - FY 2020 RTE 1st Call, #2946

NSUF Research Collaborations

Deconvoluting Void and Bubble Effects on Deformation-Induced Martensitic Transformations in Austenitic Stainless Steel Using 4D STEM Strain Mapping - FY 2023 RTE 1st Call, #4546

Effect of laser weld repairs on deformation mechanisms of neutron irradiated austenitic steels - FY 2019 RTE 1st Call, #1619

Influence of laser welding on deformation mechanisms in irradiated and weld-repaired Ni-Cr alloys - FY 2024 Super RTE Call, #5069

Irradiation Effects on Unexpected Deformation-Induced Martensitic Phase Transformation in Ni-alloys - FY 2022 RTE 1st Call, #4415

Microstructural Examination of Irradiation Effects on Metal Matrix Composite Neutron Absorber - FY 2021 RTE 1st Call, #4280

Microstructure and microchemical characterization of neutron and proton irradiated Alloy D9 using APT and TEM - FY 2017 RTE 3rd Call, #1081

Phase Characterization of Neutron Irradiated Surveillance Reactor Pressure Vessel Welds - FY 2024 RTE 1st Call, #4819

Phase Field Modeling of Irradiation-Induced Crystallization in Amorphous Nuclear Oxides - FY 2024 RTE 1st Call, #4883

Role of Irradiation Damage Cascade Descriptors on ODS and Model ODS Nanocluster Evolution - FY 2019 RTE 2nd Call, #1757

Understanding the Origin of Irradiation-Induced Yield Drop Phenomena in Grade 91 - FY 2023 RTE 2nd Call, #4703

Understanding the Remarkable Strain-Hardening Capacity of Irradiated PM-HIP 316L SS. - FY 2024 RTE 2nd Call, #4967