Radiation Effects in Metals and Ceramics: Poster Session I
Sponsored by: TMS Structural Materials Division, TMS: Nuclear Materials Committee
Program Organizers: Djamel Kaoumi, North Carolina State University; Thak Sang Byun, Oak Ridge National Laboratory; Dane Morgan, University of Wisconsin-Madison; Maria Okuniewski, Purdue University; Mahmood Mamivand; Geoffrey Beausoleil, Idaho National Laboratory; Philip Edmondson, The University Of Manchester; Khalid Hattar, University of Tennessee Knoxville; Aurelie Gentils, Université Paris-Saclay; Joel Ribis, Cea
Monday 5:30 PM
February 24, 2020
Room: Sails Pavilion
Location: San Diego Convention Ctr
H-21 (Digital): Evidence of Radiation Enhanced Diffusion via In-situ Ion Irradiation of Yttria Stabilized Zirconia Nanoparticles: Nathan Madden1; Khalid Hattar2; Jessica Krogstad1; 1University of Illinois at Urbana-Champaign; 2Sandia National Laboratories
Radiation enhanced diffusion (RED) is a general phenomenon that contributes to many of the deleterious processes in materials exposed to irradiation. Current understanding of RED is limited to simple lattices, and extension to more complicated configurations, especially those relevant to non-metallic materials, has been hampered by the complexity and difficulty of the required experiments. In this work, we leverage controlled microstructural features on the nanoscale, particularly nanoparticles, to further understand this phenomenon. In situ irradiation of nanoparticle agglomerates with 2.8 MeV gold ions were conducted in the I3TEM at Sandia National Laboratories. Under these conditions, measurable particle consolidation or sintering is observed at room temperature. This effect is moderated with increasing temperature as the thermal accommodation of irradiation induced defects competes with surface diffusion mechanisms involved in the sintering process. This nanoparticle approach provides a unique and accessible pathway to further understanding the RED phenomenon in more complex crystal structures.
H-22 (Digital): Helium Irradiation Induced Ultra-high Strength Nanotwinned Cu with Nanovoids: Cuncai Fan1; Qiang Li1; Jie Ding1; Yanxiang Liang2; Zhongxia Shang1; Jin Li1; Ruizhe Su1; Jaehun Cho1; Di Chen3; Yongqiang Wang4; Jian Wang2; Haiyan Wang1; Xinghang Zhang1; 1Purdue University; 2University of Nebraska, Lincoln; 3University of Houston; 4Los Alamos National Laboratory
In this work, we utilize the micropillar compression test to investigate the mechanical properties of He ion irradiated nanotwinned Cu with pre-existing nanovoids. In comparison with coarse-grained Cu, nanovoid nanotwinned Cu exhibits prominently improved radiation tolerance with less He bubbles and smaller dislocation loops, but it experiences higher radiation-induced strengthening. Furthermore, compression tests reveal that the irradiated NV-NT Cu has an ultrahigh yield strength of ~ 1.6 GPa with significant plasticity and detwinning at compressed micropillar tops. Post radiation analyses show that twin boundaries are decorated with He bubbles and thick stacking faults. Molecular dynamics (MD) simulation suggests that stacking fault modified twin boundaries introduce significant strengthening in nanotwinned Cu. This study provides new insights into understanding the radiation response of nanostructured metals.
H-23: Coupled Electronic and Nuclear Stopping Effects on Damage Accumulation in SiC: Lauren Nuckols1; Miguel Crespillo1; Chen Xu1; Yanwen Zhang2; William Weber1; 1University of Tennessee, Knoxville; 2Oak Ridge National Laboratory
Energy deposition from energetic ions in solids occurs through electronic and nuclear stopping. In silicon carbide (SiC), nuclear stopping is associated with ballistic induced defects, while electronic stopping can induce annealing along the ion path. Both stopping mechanisms are coupled during intermediate energy ion irradiations. Fully understanding how SiC responds to both energy dissipation mechanisms is necessary to develop and model SiC-based structural materials for fission and fusion reactors. Here, coupling between the stopping mechanisms in ion-irradiated, single crystal 4H- and 3C-SiC has been investigated using a range of ion species and energies. Damage accumulation was determined using Rutherford backscattering spectroscopy in channeling geometry (RBS/C). Ion mass, electronic energy loss magnitude, and electronic to nuclear stopping ratio all affect damage accumulation in SiC. There are thresholds in electronic stopping values for different ions above which electronic energy dissipation fully heals damage produced by elastic scattering.
H-24: Damage Evolution in Apatite Irradiated with Alpha Emitters: Dee Jay Cerico1; Frederico Garrido1; Cécile Gautheron2; Lech Nowicki3; Cyril Bachelet1; Jérôme Bourçois1; Sandrine Picard1; Aurelie Gentils1; 1CSNSM, Université Paris-Sud-CNRS; 2Géoscieces Paris-Sud, Université Paris-Sud-CNRS; 3National Centre for Nuclear Research
Apatite ceramics is a possible host matrix for actinides separated from high-level nuclear wastes. To determine the radiation tolerance of apatite to actinide decay at room temperature and at 200°C, an ion beam analysis technique known as Rutherford Backscattering Spectrometry in channeling mode (RBS/C) was utilized in this study. Through RBS/C, the individual contribution of both alpha particles and recoil nuclei to the alpha decay-induced defects creation was obtained at ion fluences ranging from a few 1012 cm-2 to a few 1017 cm-2. Damage kinetics follows a single ion direct impact model for both projectiles and the regular increase of damage level can be ascribed to the formation of radiation-induced defects. In the high fluence regime, however, the formation of overpressurized He gas bubbles plays a decisive role to the damage evolution and eventual material destabilization.
H-25: Deep Ion Implantation at the 88-Inch Cyclotron: Sarah Stevenson1; Peter Hosemann1; Lee Bernstein1; Andrew Voyles2; Saryu Fensin3; 1University of California, Berkeley; 2Lawrence Berkeley National Laboratory; 3Los Alamos National Laboratory
Ion beam implantations are widely performed to understand the effects of radiation-induced displacement damage on nuclear structural materials. Yet, the volume of material that can be investigated is often limited by the maximum energies of accelerator facilities, and it has been shown that mechanical property evaluations experience a strong size effect. The 88-Inch Cyclotron at Lawrence Berkeley National Laboratory offers a broad energy range of a variety of light- and heavy-ion beams, thereby making it possible to investigate the mechanical properties of high-dose ion beam-irradiated materials. 100 μm thick HT9 samples were implanted at the 88-Inch Cyclotron. Following irradiation, tensile tests were performed, providing a comparison of the mechanical properties to unirradiated standards. This experiment has demonstrated the capability of the 88-Inch Cyclotron to perform future deep ion implantation studies for nuclear structural materials at depths beyond what is typically available.
H-26: Defect Clustering in Irradiated Alpha Uranium: Cluster Dynamics Modeling and Ion Irradiation Experiments: Fabia Farlin Athena1; Sanjoy Majumder1; Tiankai Yao2; Lingfeng He2; Anter El-Azab1; 1Purdue University; 2Idaho National Laboratory
We present a cluster dynamics model for loop formation in alpha uranium. The defect clusters considered at prismatic loops of interstitial and vacancy type on (010) and (100) planes, respectively. The model parameters were partly taken from open literature and partly fixed by molecular dynamics simulations. Cluster dynamics simulations were carried out at different temperatures and dose rates, and the comparison with the existing neutron irradiation data for the loop size distribution and average loop size and density shows that the model is able to make reasonable predictions. We also present the results of proton irradiation of alpha uranium, where the proton beam was used to produce a microstructure dominated by dislocation loops. The formation and evolution of dislocation loops was studied by TEM technique, which provided further data for validation of the cluster dynamics model.
H-27: Defect Ordering in Yttria Stabilized Zirconia under 45 MeV Ion Irradiation: Nathan Madden1; Eric Lang1; Shannon Murray1; Jean Paul Allain1; Daniel Shoemaker1; Khalid Hattar2; Jessica Krogstad1; 1University of Illinois at Urbana-Champaign; 2Sandia National Laboratories
Most studies exploring the irradiation tolerance of yttria stabilized zirconia (YSZ) have either focused on low ion energies below 4 MeV or very high ion energies. This work aims to further develop the fundamental science of ion beam material interactions at intermediate ion energies. Observations via electron diffraction in transmission electron microscopy (TEM) have shown sublattice vacancy ordering in cubic YSZ under 45 MeV gold ion irradiation. While X-ray photoelectric spectroscopy (XPS) indicated a unique combination of zirconium oxidation states and Raman spectroscopy data includes unexpected phonon modes that are not conventionally associated with the typical polymorphs of zirconia. This ordering effect, and other observed phenomenon, are a function of the damage depth profile, corresponding to the decline in the electronic stopping power. This presentation will explore the relationship between ion energy, dosage and the likelihood of sublattice ordering, as well as the overall thermal stability of the ordered structure.
H-28: Effect of Ion Beam Irradiation on Microstructure Evolution of a Multi-metallic Layer Composite Material for Accident Tolerant Fuel Cladding Development: Taeyong Kim1; Jeonghyun Lee1; Ji Hyun Kim1; 1Ulsan National Institute of Science and Technology
Multi-Metallic Layer Composite (MMLC) cladding is being developed to replace commercial Zr cladding which is reacted with high temperature steam. Fe-12Cr-2Si alloy, which is an oxidation-resistant material, can be welded on commercial Zr tube. One or two alloy layers composed of Ti or Cr are interposed between Fe-12Cr-2Si layer and Zr layer acting as diffusion barriers to avoid eutectic phases. In this study, Si ion beam (7 MeV and 1.12×1013 ion #/cm2/s) was irradiated to the MMLC plate specimen at 445 ℃ until to obtain 5 dpa. At transmission electron microscopy analysis, as-received specimen has precipitates between Fe-12Cr-2Si and Cr layer. However, the precipitates at Si irradiated MMLC specimen have smaller size and lower number density. This is probably due to back-diffusion caused by the irradiation, and elements composing the precipitate were diffused into the surrounding grain. And Zr alloy shows segregation of Ti and Cr element into grain boundaries.
H-29: Electronic Effects in Molecular Dynamics Simulations of Ion Irradiation of SiC: Eva Zarkadoula1; German Samolyuk1; Yanwen Zhang1; William Weber2; 1Oak Ridge National Laboratory; 2University of Tennessee
Due to its physical properties, silicon carbide is a suitable material for high temperature applications and extreme radiation environments. In this work, the effects of the electronic energy loss in ion irradiation of SiC are investigated, using molecular dynamics simulations. The coupled effects of the nuclear and the electronic energy loss in the energy dissipation and damage production in primary radiation damage in SiC are discussed. The results reveal that, in the intermediate energy range, the electronic stopping results in a smaller number of surviving defects. Understanding of the primary radiation damage processes is necessary in order to be able to predict and control the material’s performance.
H-30: Equilibrium and Irradiation-induced Point-defect Disorder in ThO2 and U-doped ThO2: Modeling and Ion Irradiation Experiments: Maniesha Singh1; Tiankai Yao2; Lingfeng He2; Anter El-Azab1; 1Purdue University; 2Idaho National Laboratory
A thermodynamic defect disorder model was used to investigate the off-stoichiometry behavior in ThO2 and U-doped ThO2. The model shows that while ThO2 remains mostly hypo-stoichiometric at relevant temperature and oxygen partial pressure conditions, U doping expands the thermodynamics window over which ThO2 becomes hyper-stoichiometric, thus illustrating the impact of 5f electrons introduced by the U doping on defect disorder. For example, U0.52Th0.48O2+x can sustain disorder up to an oxygen off-stoichiometry content of x = 0.4 at high temperatures and high oxygen pressure whereas U0.2Th0.8O2+x can only exist up to an oxygen off-stoichiometry content of x = 0.05. The extent of hyper-stoichiometry in the oxide increases with decreasing temperature and increasing oxygen partial pressure values. Presented also are the results of a cluster dynamics model of vacancy and interstitial cluster formation under irradiation in conjunction with microstructure and chemical analysis of ion-irradiated ThO2 at different temperatures in TEM.
H-31: Gamma-radiation Induced Corrosion of Copper: Inna Soroka1; Mats Jonsson1; 1KTH
Repository of high-level radioactive waste is one of the key issues in a nuclear power industry. The method developed in Sweden and Finland implies multi barrier and deep geological repository concepts. Spent nuclear fuel is planned to be stored in copper canisters with iron insets. The canisters will be sealed, embedded in bentonite clay and placed in the granite bedrock at a depth of 500 m. Thus, the copper canisters will be used as one of the barriers that provides complete isolation of spent nuclear fuel from the environment for at least 100 000 years. Although, the canisters will be stored in anoxic conditions which favors copper stability, ionizing radiation is one of the parameters that influences the degradation of the copper outer shell. Hereby we investigate stability and a mechanism of gamma-radiation induced corrosion of the copper in de-aerated water.
H-32: Ionization Induced Changes in Carbon Bonding of Graphite: John Demaree1; Lenore Miller2; Zhiping Luo2; Daryush Ila2; 1CCDC Army Research Laboratory; 2Fayetteville State University
Highly oriented pyrolytic graphite (HOPG) provides an ideal platform to study the breaking and reordering of surface bonds in graphene. We studied ionization-induced changes in the bonding of HOPG from sp2 (graphitic) to sp3 (amorphous or diamondlike) using MeV ion beams with varying degrees of ionization in order to better understand phase changes in ionizing environments, as well as possibly provide a path to precise functionalization of these materials. Coupons of HOPG were bombarded with H, He, C, Si, Ag, and Au ions at energies designed to produce ionization densities from 6 to 340 eV/Å. Surfaces were examined using x-ray photoelectron spectroscopy (XPS), x-ray induced C KLL Auger spectroscopy, Raman spectroscopy, and 3D laser microscopy. The transformation of graphitic sp2 bonding to amorphous or diamondlike sp3 bonding was generally dependent on the ionization density, indicating that this transformation may be explained by ion-induced excitation and rapid thermal quenching.
H-33: Irradiation Behavior of Piezoelectric Materials for Nuclear Reactor Sensors Applications: Maha Yazbeck1; Gaofeng Sha1; Joel Hatch1; Cole Harlow1; Aleksandr Chernatynskiy2; Joshua Daw3; Marat Khafizov1; 1The Ohio State University; 2Missouri University of Science &Technology; 3Idaho National Laboratory
Piezoelectric materials are key elements of ultrasonic sensors and are attractive for instrumentation of advanced nuclear systems. Our study investigates the impact of radiation damage on physical properties of piezoelectric aluminum nitride (AlN) and lithium niobate (LiNbO3). In this presentation, we demonstrate a novel approach to perform in-situ measurement of piezoelectric material behavior under irradiation in a research reactor based on interdigital transducer surface acoustic wave resonator (SAW) devices. Observed resonant frequency shifts, proportional to the neutron flux of the SAW device, were attributed to the changes in piezoelectric, elastic, and dielectric constants of AlN and LiNbO3 caused by accumulation of defects. Reversible nature of the resonant frequency shifts, characterized by a linear increase followed by a saturating exponential decay upon step increase of neutron flux, suggests that dynamic response of the device is governed by accumulation of self-interstitials and vacancies limited by mutual recombination.
H-34: Meso-, Micro-, and Nano-scale Characterization of Neutron Irradiated U-10Zr Metallic Fuels via Synchrotron µ-CT and Electron Microscopy: Jonova Thomas1; Alejandro Figueroa1; Lingfeng He2; Xiang Liu2; Daniel Murray2; Peter Kenesei3; Jonathan Almer3; Jason Harp2; Maria Okuniewski1; 1Purdue University; 2Idaho National Laboratory; 3Argonne National Laboratory
Metallic fuels under neutron irradiation in reactors undergo severe damage and microstructural alterations. Some of these alterations include fuel constituent re-distribution, phase transformations, and formation of cavities and fission products that lead to swelling. The correlation between mesoscale characterization of neutron irradiated U-10wt%Zr (U-10Zr) fuel regions via high energy synchrotron X-rays and micro-/nano-scale characterisation via electron microscopy can be beneficial for understanding various microstructural alterations. Different localities within a U-10Zr fuel slug that has a local burnup of 5.7 at% are analyzed to provide a detailed assessment of various cavity morphologies, fuel cladding chemical interaction zones, crystal structure of phases, and local chemical compositions. Finally, an initial assessment of in-situ nano-mechanical testing at various localities of the neutron irradiated U-10Zr and HT9 (fuel/cladding) will also be presented. This systematic methodology of different length scale assessment of irradiated fuels provides a new perspective for the analysis of neutron irradiated fuels.
H-35: XCT Characterization of Neutron Irradiated SiC-SiC Composites: David Arregui-Mena1; Takaaki Koyanagi1; Gyanender Singh1; Christian Deck1; Yutai Katoh1; 1Oak Ridge National Laboratory
SiC-SiC composites are a prospective material of fuel cladding for Light Water Reactors (LWRs). This material is manufactured to withstand steam oxidation, with high strength and low neutron cross section. In this research X-ray Computed Tomography (XCT) scans of as received and neutron irradiated samples are analyzed with image segmentation. SiC-SiC composite samples with different microstructures exposed at low and high thermal flux conditions were studied to determine the performance of this type of cladding. The analysis of this data shows some of the possible microstructural changes, crack propagation and defects that may be produced by irradiation and temperature gradients. Moreover, the results obtained in this research can also be linked with thermal and mechanical properties induced by irradiation. Studies on monolithic SiC-SiC composites have been performed before, however, no work has been conducted in multi-layered SiC-SiC composites tubes, making this work unique.