Article
Nanoscience & Nanotechnology
Asanka Weerasinghe, Enrique Martinez, Brian D. Wirth, Dimitrios Maroudas
Summary: We conducted a systematic computational analysis of the mechanical behavior of tungsten in plasma-facing components (PFCs), focusing on the effects of void and helium (He) bubble defects on the mechanical response beyond the elastic regime. Our findings suggest that defective tungsten undergoes substantial softening with increasing matrix porosity and He atomic content, resulting in a decrease in the yield strength of tungsten in a monotonically decreasing fashion. We also observed that the structural response of PFC tungsten near the yield point is initiated by the emission of dislocation loops from bubble/matrix interfaces, followed by gliding and growth of these loops and reactions to form dislocations.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Review
Materials Science, Multidisciplinary
M. R. Gilbert, K. Arakawa, Z. Bergstrom, M. J. Caturla, S. L. Dudarev, F. Gao, A. M. Goryaeva, S. Y. Hu, X. Hu, R. J. Kurtz, A. Litnovsky, J. Marian, M-C Marinica, E. Martinez, E. A. Marquis, D. R. Mason, B. N. Nguyen, P. Olsson, Y. Osetskiy, D. Senor, W. Setyawan, M. P. Short, T. Suzudo, J. R. Trelewicz, T. Tsuru, G. S. Was, B. D. Wirth, L. Yang, Y. Zhang, S. J. Zinkle
Summary: Predicting material performance in fusion reactor environments relies on computational modeling supported by experiments. Leading experts discussed current positions and ongoing challenges in modeling fusion materials, highlighting topics such as irradiation-induced defect production, gas behavior, clustering, and defect evolution.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Physics, Fluids & Plasmas
Yu Li, Yuhan Sun, Long Cheng, Yue Yuan, Baohai Jia, Jiaqing He, Guang-Hong Lu, Guang-Nan Luo, Qiang Zhu
Summary: Taming the flame of nuclear fusion in a solid container remains a fundamental challenge, but high-entropy alloys may provide new solutions as plasma-facing materials. However, these alloys have disadvantages such as increased deuterium retention and decreased thermal conductivity.
Article
Materials Science, Multidisciplinary
D. Terentyev, A. Zinovev, T. Khvan, J-H You, N. Van Steenberge, E. E. Zhurkin
Summary: Designing plasma-facing components (PFC) for DEMO divertor poses new challenges for in-vessel materials, with chromium (Cr) and Cr-W alloy being considered as candidate materials for structural bodies. Alloying shows potential for increasing work hardening capacity and fracture strength, and may improve materials' resistance to irradiation. Neutron irradiation results in degradation of mechanical properties, making all materials brittle at the applied temperature, with significant modifications observed in Cr-10at.%W alloy. Fracture surface analysis is conducted to understand the nature of brittle fracture and reasons for observed brittleness.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Review
Nuclear Science & Technology
Chunyang Luo, Liujie Xu, Le Zong, Huahai Shen, Shizhong Wei
Summary: This paper analyzes the damage condition of tungsten and introduces the research on tungsten material strengthening from the aspects of solid solution alloying, dispersion strengthening, and fiber strengthening, and predicts the future research trends, especially the ability of fiber strengthening to resist irradiation.
FUSION ENGINEERING AND DESIGN
(2023)
Article
Materials Science, Multidisciplinary
J. Wu, F. Granberg
Summary: Tungsten is chosen as the material for demanding parts in fusion test reactors and power plants. Material degradation due to irradiation necessitates component replacement. Understanding how defects are formed is crucial for predicting replacement needs. Low energy simulations and Frenkel-pair insertion method are compared to investigate the potential of the latter in accelerating cascade simulations. Results show similarities qualitatively, but differences quantitatively, particularly at higher energies.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Mauro Dalla Palma, Monica Spolaore
Summary: The surface eroding thermocouples are developed for measuring temperatures and heat fluxes in plasma-facing components of fusion machines, with fast response and robust design. The improved sensor performance is achieved by enhancing the thermal contact surface between the divertor mono-block and the thermocouple carrier body. The measurement errors and installation at different poloidal positions are discussed, providing useful local information for studying divertor physics and assisting controlled terminations of plasma discharges.
IEEE SENSORS JOURNAL
(2021)
Article
Physics, Applied
R. L. Gray, M. J. D. Rushton, S. T. Murphy
Summary: The advent of high-temperature superconductors has provided the possibility of constructing smaller and cheaper fusion reactors. However, the impact of high-energy neutrons from fusion reactions on the superconductors needs to be addressed. This study uses molecular dynamics simulations to investigate the radiation-induced modifications on the crystal structure of YBa2Cu3O7, and the results show the formation of amorphous regions decorated with Cu and O defects.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Miaomiao Jin, Yipeng Gao, Chao Jiang, Jian Gan
Summary: The migration of defects in U-Mo alloys and pure metals is found to be composition-dependent, with point defect migration strongly correlated and mediated by minor atoms in alloys. Interstitial dumbbells and vacancies migrate through preferred paths, with vacancies and interstitials showing comparable diffusivity in U-rich systems. Defect diffusivity can be adjusted based on alloy composition.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Chemistry, Physical
Mehmet Fazil Kapci, J. Christian Schoen, Burak Bal
Summary: Investigations on dislocation mobility in the presence of hydrogen revealed that hydrogen decreases dislocation velocity and induces some localization. Additionally, hydrogen accumulation in the grain boundary suppresses new grain formation, leading to material hardening and potentially initiating brittle fracture points.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Nuclear Science & Technology
S. Krat, R. Selivanov, I. Sorokin, F. Podolyako, N. Sergeev, A. Alieva, D. Bachurina, M. Zaripova, M. Isaenkova, E. Fefelova, O. Volkova, V. Zaharov
Summary: Lithium-Boron Composite Material (LBCM) is a promising plasma-facing material for liquid metal first wall. It consists of approximately 20% boron and 80% lithium arranged in a Li5B4 matrix filled with metal lithium, similar to capillary porous systems (CPS). LBCM maintained its physical integrity up to temperatures above 900 degrees Celsius and showed CPS-like properties under electron and helium plasma bombardment.
NUCLEAR MATERIALS AND ENERGY
(2023)
Article
Chemistry, Physical
Xiao-Ye Zhou, Ji-Hua Zhu, Hong-Hui Wu, Xu-Sheng Yang, Shuize Wang, Xinping Mao
Summary: The study investigated the hydrogen embrittlement behavior and mechanism of nanograined materials under creep loading, finding that the deformation mechanisms are highly dependent on temperature, applied stress, and grain size. Hydrogen charging was found to inhibit grain boundary-related deformation mechanisms, and as grain size increased, the hydrogen embrittlement mechanism transitioned.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Materials Science, Ceramics
M. T. P. Rigby-Bell, A. J. Leide, V. Kuksenko, C. J. Smith, G. Zilahi, L. Gale, T. Razzell, J. Wade-Zhu, D. J. Bowden
Summary: This study investigates the stability and microstructural evolution of SiCf/SiC composites through high-energy ion irradiation and annealing experiments. The results show that the material undergoes crystallographic evolution and exhibits phenomena such as stress and lattice swelling during irradiation. However, the fibers themselves remain stable without radiation-induced defects. During annealing, bubbles in the material grow and agglomerate, but no delamination or microcracking is observed.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Physical
Zhihan Hu, Di Chen, SeungSu Kim, Rijul Chauhan, Yongchang Li, Lin Shao
Summary: The effect of stress on irradiation responses of highly oriented pyrolytic graphite (HOPG) was studied using molecular dynamics simulation, proton irradiation, and Raman characterization. The results showed that stress reduces the average threshold displacement energy, increases the damage peak and the number of surviving defects, and induces local cleavage. Experimental results also confirmed the enhanced irradiation effect caused by stress.
Article
Materials Science, Multidisciplinary
A. Fellman, A. E. Sand
Summary: This study investigates the effect of different primary recoil energies on defect formation in tungsten through molecular dynamics simulations. It is found that pre-existing radiation-induced defects modify the number of additional defects formed during cascades. Furthermore, the formation of dislocation loops in cascades is more dependent on the size of pre-existing voids rather than the energy of the primary recoil.
JOURNAL OF NUCLEAR MATERIALS
(2022)