Article
Materials Science, Multidisciplinary
Rostyslav Nizinkovskyi, Thorsten Halle, Manja Krueger
Summary: Cu-precipitation in reactor pressure vessel steels is a major concern for the degradation of mechanical properties. This study develops and implements a non-local phase-field model to investigate the equilibrium morphology of precipitates in the over-aged state. The model confirms that the precipitates should have an oblate lath-like shape, which is supported by experimental data. The orientation of the precipitates is consistent with literature. The mechanism of morphology accommodation is explained using the invariant-line method. However, the equilibrium values of elongation significantly deviate from experimental data, likely due to the metastable state of the precipitates during the coarsening process.
MATERIALS TODAY COMMUNICATIONS
(2024)
Article
Materials Science, Multidisciplinary
Taiwu Yu, Yipeng Gao, Lee Casalena, Peter Anderson, Michael Mills, Yunzhi Wang
Summary: The study investigates the influence of precipitates on the properties of NiTi-based high temperature shape memory alloys, revealing that spatially inhomogeneous stress and concentration fields have dominant effects on the martensitic transformation start temperature M-s at different aging times.
Article
Engineering, Mechanical
Jianshi Yang, Chunhui Liu, Peipei Ma, Longhui Chen, Lihua Zhan, Ning Yan
Summary: The effect of pre-deformation and post-ageing on the age hardening response and tensile properties of an Al-Cu alloy has been studied. It was found that moderate pre-deformation and specific temperature conditions can significantly improve the yield strength and uniform elongation of the alloy. Dislocations and precipitates play a major role in determining the strength of the alloy, while hard barriers can initiate void and deteriorate plasticity.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Chemistry, Physical
Fanglei Hu, Guomin Han, Baoqin Fu, Tang Shi, Xuefei Huang
Summary: An elastoplastic phase-field model was used to study stress-assisted diffusional phase transformation with plastic deformation. Different loading conditions were applied to a single crystal during precipitation to investigate the effects on elastoplastic deformation and phase transformation. Simulation results showed that plastic deformation may occur even below the materials' yield limits due to stress accumulation triggered by volume expansion and lattice mismatch. Plasticity played a significant role in the morphological evolution of the precipitate under axial and shear loading, with different shapes observed compared to no loading conditions. Plasticity had a dual role in promoting initial growth but later impeding it. These findings provide guidelines for designing precipitate microstructures for better mechanical properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Fanglei Hu, Guomin Han, Baoqin Fu, Tang Shi, Xuefei Huang
Summary: An elastoplastic phase-field model was developed to investigate diffusional transformations in Mg-Al-based alloys. The model considers plastic deformation and its effects on the morphology and growth kinetics of beta-Mg17Al12 precipitates. The modeling results show that plastic deformation has a dual effect on the growth of the precipitate, promoting it during the initial stage but retarding it afterward.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
R. Santos-Guemes, L. Capolungo, J. Segurado, J. LLorca
Summary: Dislocation dynamics simulations were used to determine the critical resolved shear stress of an Al 4 wt. % Cu alloy containing theta'' precipitates, with results in good agreement with experimental data. The optimal strength of the alloy was found to be achieved with a homogeneous distribution of theta'' precipitates at an average size transitional between shearing and looping. Overall, the strategy presented in this study provides quantitative predictions of precipitate strengthening in metallic alloys.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Materials Science, Multidisciplinary
Tengwu He, Xiuhua Chen, Yuming Qi, Miaolin Feng
Summary: This study utilizes a phase-field model and thermodynamic databases to explore the microstructural evolution in multi-principal element alloys. The simulated results reveal a complex core-shell structure in the Cu-enriched phase, with a retardant effect from the Ni/Fe shell. High Ni/Fe concentration delays the growth and coarsening of the Cu-enriched phase, while high temperature accelerates these processes.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Chemistry, Physical
Munzali Musa, Xin Song, Xianglong Zhou, Wentao Jia, Tao Yuan, Tianyu Ma, Xiaobing Ren
Summary: Grain boundaries with sparse 1:5H precipitates are considered as the primary demagnetization sites in pinning-controlled 2:17-type Sm-Co-Fe-Cu-Zr permanent magnets, leading to poor magnetic properties. TEM investigations reveal that grain boundary regions contain larger 2:17R nanovariants, less SFs, and fewer defects-aggregated cell boundaries compared to grain interiors, indicating that early decomposition preferably occurs at grain boundaries.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Multidisciplinary
Arya Chatterjee, Dmitry Popov, Nenad Velisavljevic, Amit Misra
Summary: In this study, a state-of-the-art additive manufacturing system was used to produce a custom-built 50Cu-50Fe alloy. High-pressure compression experiments were conducted to investigate the structural stability and deformation of the material. The results showed that the Fe phase remained stable up to a certain pressure, while Cu undergoes a structural transition. This work highlights the potential of additive manufacturing for tailored functional materials and extreme stress/deformation applications.
Article
Engineering, Mechanical
Xiaojing Zuo, Nele Moelans
Summary: We propose a new approach to model the stress effects in high and medium entropy alloys using a combination of phase-field method, CALPHAD data and DFT calculations. By calculating the composition dependent Gibbs energies and diffusion mobilities of the BCC and FCC phase, and studying the elastic properties using DFT, we investigate the evolution of the BCC/FCC microstructures in AlCrFeNi alloys. It is found that the elastic stresses arising from the difference in eigenstrain between the BCC and FCC phases have a significant impact on precipitate formation.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Nanoscience & Nanotechnology
Kang Du, Yang Zhang, Zhongwu Zhang, Tao Huang, Guangda Zhao, Liyuan Liu, Xiyu Wang, Lixin Sun
Summary: This paper systematically investigated the effects of V on the formation of precipitates and mechanical properties in Fe-Ni-Co-Al-Nb alloy. It was found that the addition of V can improve the strength by forming nano-sized gamma' precipitates, and significantly improve the elongation of the alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Metallurgy & Metallurgical Engineering
Liu Xuxi, Liu Wenbo, Li Boyan, He Xinfu, Yang Zhaoxi, Yun Di
Summary: In this study, the critical nucleus size and minimum energy path of Cu-riched precipitate in Fe-Cu alloy under irradiation were calculated, and the effects of temperature and Cu concentration on the energy path and critical nucleus cluster size were studied. It was found that temperature mainly influences the energy path direction, while Cu concentration mainly affects the growth rate of the nucleus radius. The distribution of Cu concentration also impacts the distribution of vacancy during radiation.
ACTA METALLURGICA SINICA
(2022)
Article
Chemistry, Multidisciplinary
Vasiliy S. Krasnikov, Alexander E. Mayer, Victor V. Pogorelko, Marat R. Gazizov
Summary: The study investigates the prolonged plastic deformation of aluminum containing theta' phase using a multistage approach combining MD, CM, and DDD. It is found that damage to the crystal structure of inclusions and activation of cross-slip of dislocation segments lead to a decrease in acting stresses in the MD system. The softening effect of inclusions is further introduced into the dislocation-precipitate interaction, causing a decrease in flow stress during deformation.
APPLIED SCIENCES-BASEL
(2021)
Article
Nanoscience & Nanotechnology
S. Y. Peng, Y. Z. Tian, Y. Yang, M. Jiang, H. X. Li, J. W. Wang, S. Li, G. W. Qin
Summary: In this study, a powder rolling strategy was successfully used to fabricate fully dense Cu-10Fe billet, solving the challenges of Fe macrosegregation during casting and limited sample size in traditional powder metallurgy methods. The microstructure evolution at different processing stages was characterized, revealing the successful avoidance of Fe macrosegregation and the achievement of good metallurgical bonding quality between powders. Moreover, the formation mechanisms of ordered structures and precipitates were analyzed, and the variation of mechanical and electrical properties with aging process was discussed.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
Wen Fu, Chengning Li, Xinjie Di, Kuijun Fu, Heshan Gao, Chao Fang, Siyao Lou, Dongpo Wang
Summary: The effect of Mo element on the precipitation behavior of nanoscale Cu-rich particles in Cu-bearing low carbon high strength steels was investigated. It was found that the addition of Mo refined the size of grain interior Cu-rich particles and inhibited the formation of grain boundary Cu-rich particles. The enrichment of Mo in the matrix suppressed the diffusion of Cu atoms and merger of Cu-rich particles. The CuMo-bearing steel showed increased yield strength and suppressed crack initiation and propagation at grain boundaries, leading to an increment in absorbed energy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
P. Frint, M. Hockauf, D. Dietrich, T. Halle, M. F. -X. Wagner, T. Lampke
MATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK
(2011)
Article
Materials Science, Multidisciplinary
K. Hockauf, L. Koehler, M. Haendel, T. Halle, D. Nickel, G. Alisch, T. Lampke
MATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK
(2011)
Article
Materials Science, Multidisciplinary
K. Hockauf, M. Hockauf, M. F. -X. Wagner, T. Lampke, T. Halle
MATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK
(2012)
Article
Materials Science, Multidisciplinary
P. Frint, M. Hockauf, T. Halle, M. F. -X. Wagner, T. Lampke
MATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK
(2012)
Article
Mechanics
Lothar W. Meyer, Thorsten Halle
MECHANICS OF TIME-DEPENDENT MATERIALS
(2011)
Article
Materials Science, Multidisciplinary
Konstantin Naumenko, Elisabetta Gariboldi, Rostyslav Nizinkovskyi
MECHANICS OF MATERIALS
(2020)
Article
Materials Science, Multidisciplinary
Christoph Roessler, David Schmicker, Oleksii Sherepenko, Thorsten Halle, Markus Koerner, Sven Juettner, Elmar Woschke
Article
Materials Science, Multidisciplinary
Maximilian Regenberg, Georg Hasemann, Markus Wilke, Thorsten Halle, Manja Krueger
Article
Materials Science, Multidisciplinary
Markus Haertel, Alisa Wilke, Sebastian Dieck, Pierre Landgraf, Thomas Grund, Thomas Lampke, Heiko Neukirchner, Thorsten Halle, Sebastian Wappler
Summary: The study investigated the potential of a commercial spring steel in terms of Q&P heat treatment and found that not only the volume fraction and fine distribution of retained austenite affect the improvement of mechanical properties, but also the process step when the retained austenite is developing and the occurrence of parallel formation of carbides can strongly influence this potential.
Article
Engineering, Mechanical
Maria Herbster, Rostyslav Nizinkovskyi, Miriam Bollmann, Dirk Bartel, Christoph H. Lohmann, Manja Krueger, Thorsten Halle, Jessica Bertrand
Summary: The rheological properties of synovial fluid have a significant impact on the friction and wear performance of total joint replacements. Synthetic fluid constituents, such as hyaluronic acid, were found to play a crucial role in shear-thinning behavior. Mathematical modeling allowed for reliable simulation of human synovial fluid flow, highlighting the need for modified lubricants in in vitro wear tests for accurate representation of clinical conditions.
Proceedings Paper
Materials Science, Multidisciplinary
Sibylle Stark, Martin Beutner, Falk Lorenz, Thomas Lampke, Bernhard Karpuschewski, Thorsten Halle
MATERIAL FORMING - ESAFORM 2012, PTS 1 & 2
(2012)
Article
Engineering, Manufacturing
Reimund Neugebauer, Lothar W. Meyer, Thorsten Halle, Mike Popp, Sebastian Fritsch, Christopher John
PRODUCTION ENGINEERING-RESEARCH AND DEVELOPMENT
(2011)
Article
Materials Science, Multidisciplinary
Liuming Wei, Jingwen Li, Yonggang Li, Qirong Zheng, Fan Cheng, Chuanguo Zhang, Jingyu Li, Gaofeng Zhao, Zhi Zeng
Summary: This study investigates the influence of He-V complexes on H behaviors on different W surfaces using DFT calculations. The results show that H dissolution is most difficult but H trapping is easiest on the W (110) surface, while the opposite is true on the W (111) surface. Moreover, the presence of He-V complexes increases the difficulty of H diffusion from bulk to surface and desorption.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Yan Meng, Song Zeng, Chen Chen, Chaowen Zhu, Huahai Shen, Xiaosong Zhou, Xiaochun Han
Summary: The characteristics of magnetron sputtered Cr coatings vary with different temperature, bias voltage, and pressure. Coatings with random orientation, good crystallinity, and small grain size exhibit favorable oxidation behavior, while coatings with strong (200) texture, poor crystallinity, and large grains have many intrinsic defects that are detrimental to the protection property of the Cr coatings.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Xinyuan Xu, Zefeng Yu, Wei-Ying Chen, Aiping Chen, Arthur Motta, Xing Wang
Summary: This study presents an automated approach for characterizing grain morphology in TEM images recorded during ion irradiation. By combining a machine learning model and a computer vision algorithm, comparable results to human analysis can be achieved with significantly reduced analysis time. Researchers can train their own models following the procedures described in this study to automate grain morphology analysis of their own TEM images.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Shihao Wu, Dong Wang, Yapei Zhang, Koji Okamoto, Marco Pellegrini, Wenxi Tian, Suizheng Qiu, G. H. Su
Summary: The oxidation and degradation mechanisms of Cr coating on Zr alloy cladding under high temperature steam atmosphere are summarized, and a mathematical analysis model is established to predict the changes in coating thickness. The model is applied in the analysis of structure evolution under different conditions.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
V. Diaz-Mena, J. de Prado, M. Roldan, I. Izaguirre, M. Sanchez, M. Rieth, A. Urena
Summary: The brazeability of a cupronickel alloy was evaluated as a filler alloy for high-temperature joining of tungsten to steel. The study investigated the brazing conditions and the impact of the selected filler on the joint quality using numerical software. The results showed different metallurgical interactions and diffusion phenomena between the filler alloy and the base materials at different temperatures. The study emphasized the importance of selecting a suitable filler to mitigate residual stresses in the joints.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Pengcheng Zhu, Yajie Zhao, Yan-Ru Lin, Jean Henry, Steven J. Zinkle
Summary: This study investigates the effect of heavy-ion irradiation on radiation hardening in high-purity binary alloy Fe18Cr. Nanoindentation testing and high-quality TEM imaging were conducted to extract hardness and microstructure information. The strength factor was accurately calculated based on the detailed TEM characterization of irradiated microstructures, and a refined hardening superposition method was applied to quantify the mechanical properties of ion-irradiated materials.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Bin Wu, Haixia Ning, Hanzhen Zhu, Jianjun Chen, Kang Wang, Daiyu Zhang, Fu Wang, Qilong Liao
Summary: This study discusses the effects of ZrO2 and B2O3 on the phase composition and properties of SAP-based glass-ceramics. The results show that ZrO2 addition improves the formation of NZP phase while restricting the crystallization of AlPO4 phases. The correct ratios of ZrO2 and B2O3 allow only the formation of NZP phase within the SAP glass.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Hwasung Yeom, Greg Johnson, Benjamin Maier, Tyler Dabney, Kumar Sridharan
Summary: Cr-Nb bilayer coatings were developed using cold spray deposition to improve the limiting operational temperature of Cr-coated Zr-alloy system. The coatings exhibited outstanding oxidation resistance at high temperatures and formed continuous intermetallic compound layers at the interfaces.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Padhraic L. Mulligan, Andrew T. Nelson, Chad M. Parish, Patrick A. Champlin, Xiang Chen, Daniel Morrall, Jason M. Harp
Summary: Environmental barrier coatings are being developed to reduce oxidation and embrittlement in Zr-based materials. Chromium nitride is a candidate for this application, but understanding its impact on irradiation-induced creep and microstructure is critical.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Dexuan Yan, Xinlei Cao, Ke Shen
Summary: This study investigated the purification mechanism of polycrystalline graphite by comparing IG-11 graphite with IG-110 nuclear grade graphite. The analysis revealed that metallic impurities in IG-11 were primarily segregated within graphite porosities, while IG-110 demonstrated a significant reduction in impurities. This research contributes to the development of innovative graphite purification techniques for greater purity and stronger oxidation resistance.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Wei Xu, Wei Peng, Lei Shi, Qi Sun
Summary: This paper investigates the oxidation and shape evolution of matrix graphite in high temperature gas-cooled reactors during air-ingress accidents. A reaction kinetics model is established and computational fluid dynamics with a dynamic mesh method is used to simulate the oxidation process. The results show that the geometric shape of graphite changes significantly with increasing flow rate, and the graphite pebbles tend to form a structure with a narrow front and wide tail.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Allison Harward, Casey Elliott, Michael Shaltry, Krista Carlson, Tae-Sic Yoo, Guy Fredrickson, Michael Patterson, Michael F. Simpson
Summary: This paper investigates the hygroscopic properties of eutectic LiCl-KCl absorbed into zeolite-4A. The study finds that water absorption and corrosion worsen with increasing salt loading. It also suggests that the salt can be stored in a non-inert atmosphere for a certain period of time.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Takaaki Koyanagi, Xunxiang Hu, Christian M. Petrie, Gyanender Singh, Caen Ang, Christian P. Deck, Weon-Ju Kim, Daejong Kim, James Braun, Yutai Katoh
Summary: This study provides critical experimental data on the effects of irradiation on the hermeticity of SiC composite cladding, finding that irradiation can cause a decrease in hermeticity and cracking, and coating the outer surface can mitigate the cracking issue.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
S. Krat, A. Prishvitsyn, Yu. Gasparyan
Summary: This study proposes a probabilistic and diffusion-based model to describe the co-deposition of multiple hydrogen isotopes with slowly grown metal layers. The model calculates the relative concentrations of different hydrogen isotopes in the co-deposited metal layers. It is found that if hydrogen isotopes have different detrapping energies, only the isotope with the highest detrapping energy shows a monotonic decrease in concentration with deposition temperature. Furthermore, the study evaluates the uncertainty of tritium concentration in the co-deposited layer based on the uncertainty in detrapping energy of tritium and deuterium, predicting a >10% tritium concentration uncertainty for a 0.01 eV difference.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Tijo Vazhappilly, Arup Kumar Pathak
Summary: This study investigates the effect of Ce atom substitution in UO2 on its thermophysical properties using density functional theory. The results show that the Ce substitution levels and the oxidation state of Ce/U atoms strongly influence the band structure and specific heat capacity of the UO2 lattice. These findings provide important insights into the fuel properties of UO2 under reactor conditions.
JOURNAL OF NUCLEAR MATERIALS
(2024)