Associate Professor, Department of mechanical Engineering, University of Idaho. B.S., Oregon State University (1999); M.Engr., Grad. Teaching Certificate, and Ph.D. in Materials Science and Engineering, Boise State University (2016 and 2017). P.E. license #17669 (Idaho) since 2017, P.E. license #60190PE (Oregon) since 2004. Prior roles include: Platform Leader, Engineering Manager, and Project Engineer at Hyster-Yale Materials Handling, Inc. (2004-2013); Engineering Manager, and Design Engineer at GK Machine, Inc. (1999-2004). In present position: Director of Interdisciplinary Engineering Capstone Design Program, Co-op advisor for mechanical engineering. Teaching: Interdisciplinary capstone design, Machine design and Material selection and design. Member of: TMS, ANS MSTD, NSUF User’s Organization Executive Committee. Several publications on radiation effects in ferritic-martensitic and ODS alloys, with focus on atom probe tomography characterization of nanocluster and secondary phase evolution upon irradiation.
"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 | ||
"APT characterization and modeling of irradiation-induced Nb-rich nanoclustering in Zr-1.0%Nb alloys" Matthew Swenson, Saheed Adisa, Materialia Vol. 16 2019 Link | ||
"Collected data set size considerations for atom probe cluster analysis" Janelle Wharry, Matthew Swenson, Microscopy & Microanalysis Vol. 22 2016 690 Link | ||
"Comparison of microstructure evolution in Fe2+ or neutron-irradiated T91 at 500 C"
Matthew Swenson, Saheed Adisa, Ryan Blair,
Materialia
Vol. 12
2020
100770
Link
The objective of this study is to evaluate dose rate effects on microstructure evolution in ferritic-martensitic alloy T91 following neutron or Fe2+ irradiation to a common dose (3 dpa) and temperature (500 °C). Characterization via TEM and APT is also conducted following Fe2+ irradiation to 100 dpa at 500 °C. Dislocation loop morphologies are consistent following each irradiation to 3 dpa, with only minor growth observed at 100 dpa. Each irradiation exhibits favorability for a<100> loops over a/2<111>. Si-Mn-Ni-rich and Cu-rich nanoclusters are more coarsely distributed following Fe2+ irradiation, while the same solutes exhibit strong evidence of segregation to grain boundaries, dislocation loops, and dislocation lines following both irradiations to 3 dpa. However, after 100 dpa, solutes are likely redistributed. While the invariance theory likely explains dislocation loop evolution with variations in dose rate, it is not sufficient to predict temperature shift requirements for solute cluster evolution at 3 dpa. |
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"Comparison of microstructure evolution in Fe2+ or neutron-irradiated T91 at 500°C" Ryan Blair , Saheed Adisa, Matthew Swenson, Materialia Vol. 12 2020 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 | ||
"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 | ||
"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. |
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"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. |
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"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 | ||
"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. |
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"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. |
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"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. |
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"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. |
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"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. |
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"Understanding plasticity in irradiated alloys through TEM in situ compression pillar tests" Kayla Yano, Priyam Patki, Matthew Swenson, Journal of Materials Research Vol. 35 2020 1037-1050 Link | ||
"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 |
"A predictive model for irradiation-induced nanocluster evolution in b.c.c. Fe-based alloys" Matthew Swenson, Janelle Wharry, TMS Annual Meeting 2017 [unknown] | |
"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] | |
"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) | |
"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) | |
"Modeling of irradiation-induced precipitates in ferritic-martensitic alloy T91" Matthew Swenson, Saheed Adisa, National Society of Black Engineers Annual Convention March 27-31, (2018) | |
"Modeling temperature shift for solute clustering in T91 when using variable dose rate irradiations" Matthew Swenson, Saheed Adisa, TMS March 10-14, (2019) | |
"Study of Niobium clustering in Zr-1.0%Nb alloy irradiated with Kr2+ ions or neutrons to ~9 dpa at 310 °C" Matthew Swenson, Saheed Adisa, Jing Hu, TMS 2020 Annual Meeting February 23-27, (2020) | |
"Temperature shift evaluation for G-phase clustering in ferritic-martensitic alloys" Matthew Swenson, Saheed Adisa, TMS 2020 Annual Meeting February 23-27, (2020) | |
"Temperature shift for emulating solute cluster evolution using higher dose rate irradiation" Matthew Swenson, Janelle Wharry, TMS 2018 March 11-15, (2018) |
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 |
NSUF awards 30 Rapid Turnaround Experiment proposals - Approximately $1.53M has been awarded. Tuesday, June 14, 2022 - Calls and Awards |
This NSUF Profile is 75
Authored 10+ NSUF-supported publications
Top 5% of all NSUF-supported presenters
Submitted an RTE Proposal to NSUF
Top 5% of all RTE Proposals awarded
Collaborated on an RTE Proposal
Reviewed 10+ RTE Proposals
Characterization and modeling of secondary phase evolution in an irradiated Zr-1.0Nb alloy - FY 2018 RTE 2nd Call, #1400
Influence of laser welding on deformation mechanisms in irradiated and weld-repaired Ni-Cr alloys - FY 2024 Super RTE Call, #5069
Irradiation effects on microstructure and mechanical properties in a laser welded ODS alloy - FY 2022 RTE 1st Call, #4389
Irradiation-induced solute clustering behavior in ferritic/martensitic alloy T91 - FY 2018 RTE 1st Call, #1210
Modeling nanocluster evolution in irradiated ferritic ODS and ferritic/martensitic alloys - FY 2016 RTE 3rd Call, #710
Temperature shift evaluation for G-phase nanocluster evolution in ferritic/martensitic alloys - FY 2019 RTE 2nd Call, #1765
Understanding the effects of irradiation dose rate and particle type in Ferritic/Martensitic alloys - FY 2016 RTE 1st Call, #625
The Nuclear Science User Facilities (NSUF) is the U.S. Department of Energy Office of Nuclear Energy's only designated nuclear energy user facility. Through peer-reviewed proposal processes, the NSUF provides researchers access to neutron, ion, and gamma irradiations, post-irradiation examination and beamline capabilities at Idaho National Laboratory and a diverse mix of university, national laboratory and industry partner institutions.
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