NSUF - Nuclear Science User Facilities

Andrew Hoffman

Profile Information
Name
Dr. Andrew Hoffman
Institution
Catalyst Science Solutions
Position
Chief Innovation Officer
Affiliation
Catalyst Science Solutions
h-Index
ORCID
0000-0003-1915-2971
Expertise
Atom Probe Tomography, Corrosion, EBSD, FIB, Mechanical Properties, Post Irradiation Examination (PIE), SEM, TEM, X-Ray Diffraction
Publications:
"Effects of Al and Ti Additions on Irradiation Behavior of FeMnNiCr Multi-Principal-Element Alloy" Andrew Hoffman, Haiming Wen, Li He, Kumar Sridharan, Matthew Luebbe, Jiaqi Duan, JOM Vol. 72 2020 150-159
Two Co-free multi-principal-element alloys (MPEAs), viz. single-phase face-centered cubic (FCC) Fe30Ni30Mn30Cr10 and (Fe30Ni30Mn30Cr10)94Ti2Al4 (all in atomic percent) with FCC matrix containing Ni-Ti-Al enriched L12 (ordered FCC) secondary phase (γ′), have been developed and investigated. The alloys were ion irradiated at 300°C and 500°C to peak damage of 120 displacements per atom (dpa). Compared with the (Fe30Ni30Mn30Cr10)94Ti2Al4 alloy, in the Fe30Ni30Mn30Cr10 alloy, the dislocation loops were smaller, with a higher number density. The difference in loop size between the two MPEAs was attributed to the addition of Ti to the matrix, which was anticipated to lower the stacking fault energy and stabilize the faulted Frank loops. The γ′ phase showed good stability under irradiation, with no new γ′ precipitation or growth in existing precipitates. Both alloys showed similar irradiation-induced hardening at 300°C, but the (Fe30Ni30Mn30Cr10)94Ti2Al4 alloy exhibited lower irradiation-induced hardening at 500°C compared with the Fe30Ni30Mn30Cr10 alloy.
"Effects of the Tempering and High-Pressure Torsion Temperatures on Microstructure of Ferritic/Martensitic Steel Grade 91" Artur Ganeev, Marina Nikitina, Vil Sitdikov, Rinat Islamgaliev, Andrew Hoffman, Haiming Wen, Materials Vol. 11 2018 Link
"Enhanced Resistance to Irradiation Induced Ferritic Transformation in Nanostructured Austenitic Steels" Andrew Hoffman, Maalavan Arivu, Haiming Wen, Li He, Kumar Sridharan, Xin Wang, Xiang Liu, Lingfeng He, Yaqiao Wu, Materialia Vol. 13 2020 Link
Irradiation induced phase transformation of γ-austenite to α-ferrite has been observed in austenitic steels for the past several decades. This transformation can be detrimental to structural materials in a nuclear reactor environment as the increased fraction of the ferritic phase can increase corrosion and embrittlement and lead to stress corrosion cracking. This transformation is caused by both strain induced martensite transformation as well as radiation induced segregation and precipitation. In this study, two radiation tolerant nanostructured 304L austenitic steels (one ultrafine grained and one nanocrystalline) were manufactured using severe plastic deformation. These nanostructured 304L steels were compared to conventional coarse-grained 304L, after self-ion irradiation at 500°C up to a peak damage of 50 displacements per atom. Phase fraction after irradiation was analyzed using grazing incidence x-ray diffraction, precession electron diffraction, and electron backscatter diffraction. Nanostructured 304L steels showed significant resistance to irradiation induced austenite to ferrite transformation. This resistance was shown to be due to a decrease in defect formation, as well as a reduction in radiation induced segregation and precipitation.
"FeCrAl fuel/clad chemical interaction in light water reactor environments" Andrew Hoffman, Journal of Nuclear Materials Vol. 587 2023 Link
This article investigates the fuel-cladding chemical interaction (FCCI) behavior of two commercial FeCrAl alloys, APMT composition (Fe-21Cr-5Al-3Mo wt.%) and C35M (Fe-13Cr-5Al-2Mo-0.2Si-0.03Y wt.%), after neutron irradiation. “H-cup” diffusion multiples of FeCrAl alloys and ceramic UO2 fuel were irradiated at a temperature of ∼300 °C to a total estimated burnup of 26 GWd/tHM. Post-irradiation Examination results demonstrate the excellent degradation resistance of FeCrAl alloys as accident tolerant fuel (ATF) cladding materials in light water reactor conditions. The study concludes that there was no irradiation-induced defects observed in either of the two commercial FeCrAl claddings. The formation of amorphous Al/U mixed oxide was observed at the fuel-clad interface, which can serve as a tritium permeation barrier and protect against potential chemical attack from the fuel. The study attributed the formation of amorphous Al/U mixed oxide to the low temperature and limited time of neutron irradiation. APMT forms more distinct Cr and Cr-Fe intermetallic at the FeCrAl-UO2 interface than C35M due to the higher bulk Cr:Al ratio.
"High-pressure Torsion Assisted Segregation and Precipitation in a Fe-18Cr-8Ni Austenitic Stainless Steel" Andrew Hoffman, Haiming Wen, Rinat Islamgaliev, Ruslan Valiev, Materials Letters Vol. 243 2019 116-119 Link
"Severe plastic deformation assisted carbide precipitation in Fe-21Cr-5Al alloy" Maalavan Arivu, Andrew Hoffman, Jiaqi Duan, Haiming Wen, Rinat Islamgaliev, Ruslan Valiev, Materials Letters Vol. 253 2019 78-81 Link
Presentations:
"Effects of severe plastic deformation and irradiation on precipitation in ultrafine-grained steels studied using atom-probe tomography" Andrew Hoffman, Haiming Wen, 2019 TMS Annual Meeting March 10-14, (2019)
"Effects of Ti and Al Additions on Irradiation Behavior of FeMnNiCr Based High Entropy Alloys" Andrew Hoffman, Haiming Wen, Li He, Kumar Sridharan, 2019 TMS Annual Meeting March 10-14, (2019)
"Effects of Ti and Al Additions on Irradiation Behavior of FeMnNiCr Based High-Entropy Alloys" Matthew Luebbe, Andrew Hoffman, Hans Pommeranke, Li He, Kumar Sridharan, Haiming Wen, Materials Science & Technology 2019 September 29-3, (2019)
"Enhanced Austenite Stability in Nanostructured Steels During Ion Irradiation" Andrew Hoffman, Haiming Wen, Maalavan Arivu, 2020 TMS Annual Meeting February 23-27, (2020)
"Microstructure evolution in irradiation-tolerant ultrafine-grained steels" Haiming Wen, Andrew Hoffman, Jiaqi Duan, 2019 TMS Annual Meeting March 10-14, (2019)
NSUF Articles:
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 Awards 37 RTE Proposals - Awarded projects total nearly $1.4M in access awards Tuesday, July 14, 2020 - News Release, Calls and Awards
U.S. Department of Energy Announces FY21 CINR Awards - DOE has selected 4 NSUF projects U.S. Department of Energy (DOE) selected four projects that will take advantage of Nuclear Science User Facilities (NSUF) capabilities to investigate important nuclear fuel and material applications. Monday, June 28, 2021 - Calls and Awards

About Us

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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