Article
Materials Science, Multidisciplinary
Hiroshi Oka, Takashi Tanno, Yasuhide Yano, Satoshi Ohtsuka, Takeji Kaito, Naoyuki Hashimoto
Summary: 9Cr oxide dispersion strengthened steels with different nitrogen concentrations were investigated for their creep behavior at 973K. It was found that the creep strength decreased significantly with increasing nitrogen concentration. Microstructural analysis revealed the presence of coarse Y-rich inclusions in the specimens with higher nitrogen concentrations. Furthermore, rows of creep voids were observed near the rupture part of the specimens, and their fraction increased with increasing nitrogen concentration.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
M. Klimenkov, U. Jaentsch, M. Rieth, M. Duerrschnabel, A. Moeslang, H. C. Schneider
Summary: The study analyzed the microstructure of EUROFER-ODS alloy with 0.5% Y2O3 under neutron irradiation using transmission electron microscopy. It found that small loops and point defects are preferentially located near structural defects, and the distribution of loops depends on the size and number density of the particles.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Hiroshi Oka, Takashi Tanno, Yasuhide Yano, Satoshi Ohtsuka, Takeji Kaito, Yoshiaki Tachi
Summary: The microstructure of 9Cr oxide dispersion strengthened tempered martensitic steel (TMS) cladding and 12Cr-ODS ferritic steel cladding after very long-term internal pressurized creep tests was observed. The stability of martensite and ferrite matrix structure, including carbide distribution and nano-particle distribution, were investigated. Results confirmed that nano-particles were stably present during high-temperature and very long-term stress loading, contributing to preventing matrix structure degradation and excellent creep strength of the materials.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Ratnakar Singh, Ujjwal Prakash, Deepak Kumar, Kinkar Laha
Summary: The creep behavior of a high yttria Fe-18Cr-2W-0.57Ti-1Y(2)O(3) ferritic oxide dispersion strengthened (ODS) steel produced by powder forging was investigated. Creep tests were conducted at temperatures ranging from 873 K to 1023 K and stresses ranging from 150 MPa to 425 MPa. The results showed high stress exponents and activation energy, indicating the presence of threshold stress due to the interaction between dislocations and oxide particles. The microstructure of the ODS steel remained stable after creep with no significant coarsening of nano size oxide particles.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Huan Yan, Xiang Liu, Lingfeng He, James Stubbins
Summary: In this experiment, the microstructure evolution and hardening mechanism of Fe-9Cr F/M steel T91 under neutron irradiation in different temperature ranges were studied. The results show significant coarsening of Ni/Si/Mn clusters and fast coalescence of dislocation loops at high temperatures.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Nuclear Science & Technology
Ke Shi, Wei Zhang, Zhien Ning, Hui Wang, Jiali Liao, Yuanyou Yang, Ning Liu, Jijun Yang
Summary: The study observed that proton and Au-ion irradiation resulted in different types of dislocation structures and voids in F/M steel. Additionally, hardening effects were present in the irradiated F/M steel samples.
NUCLEAR MATERIALS AND ENERGY
(2021)
Article
Materials Science, Multidisciplinary
Ziyang Xie, Liping Guo, Yiheng Chen, Yunxiang Long, Pengfei Lv, Fang Li, Hongtai Luo, Wenbin Lin, Zepeng Yin, Junjie Cao, Zhangjian Zhou, Hui Wang, Shaobo Mo
Summary: Simultaneous Fe + He ion irradiations of CLAM and ODS-F/M steels were conducted to investigate the effect of oxide particles on the evolution of He bubbles and dislocation loops. The results showed that the average size of oxide particles decreased and the density increased after irradiation. He bubbles were observed at the edge of oxide particles, and their aggregation increased with increasing He concentration. ODS-F/M steel exhibited better inhibition on the growth of dislocation loops compared to CLAM steel, but this inhibitory effect decreased with increasing temperature and He concentration.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Johan Ewald Westraadt, William Edward Goosen, Aleksander Kostka, Hongcai Wang, Gunther Eggeler
Summary: The formation of modified Z-phase in a 12Cr1MoV tempered martensite ferritic steel during creep testing at high temperature and stress was investigated. The results showed that the modified Z-phase precipitated in both the uniformly-elongated gauge and thread regions of the fractured sample. Localized creep-strain strongly promoted the formation of the modified Z-phase.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Ashwani Kumar, Jayabalan Bhagyaraj, Amit Prasad, Jayant Jain, Subrata Mukherjee, Krishanu Biswas, Sudhanshu S. Singh
Summary: In this study, tungsten and lanthana containing ODS steels were synthesized by mechanical alloying and spark plasma sintering. The results showed that increasing sintering temperature improved both the density and hardness of the alloys. Transmission Electron Microscopy analysis revealed nano-sized precipitates composed of La, Ti, and Cr. Comparisons with other ODS steels demonstrated that the tungsten containing alloy exhibited higher hardness and compressive strength.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Qian Yuan, Ankur Chauhan, Ermile Gaganidze, Jarir Aktaa
Summary: The study revealed that post-irradiation annealing at 600 degrees Celsius can effectively reduce the dislocation loop density and increase the average size of loops in 9%Cr reduced-activation ferritic-martensitic steel. The annealing kinetics of loops is significantly affected by the spontaneous evolution of loops neighboring microstructure, as well as the type of loops, segregation of alloying elements, and the presence of free surface.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Tian-xing Yang, Peng Dou, Peng Zhang, Yong-chun Yang
Summary: Fe-Cr oxide dispersion strengthened (ODS) steel is a promising material for high burn-up fuel cladding of advanced nuclear reactors due to its exceptional high temperature strength and resistance to various harmful factors. In this study, the matrix structure and oxides in 11Cr ferritic/martensitic (F/M) ODS steel were investigated using advanced electron microscopy techniques. The results revealed that the dispersion morphology of oxides in the residual ferrite phase is superior to that in the tempered martensite phase, with smaller particle size and spacing, higher number density, and volume fraction. The phase identifications and proportions of different oxides were determined for both phases. The coherency and crystallographic orientation relationships between the oxides and the ferrite matrix were observed, while such relationships were occasionally detected in the martensite matrix. The mechanisms of oxide formation, polymorphic transition, and strengthening in the 11Cr F/M ODS steel were further discussed.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Dechang Zhang, Junjie Shen, Bo Li, Taotao Ruan, Zhihang Zhao
Summary: This study investigates the deformation behavior of 430 ferritic stainless steel during high-temperature uniaxial creep experiments. The microstructure is analyzed after creep deformation using scanning electron microscopy, energy-dispersive spectroscopy, electron backscatter diffraction, and transmission electron microscopy. The creep curves show a Normal type pattern with a creep stress exponent of 3.6-6.7 and a creep activation energy of 476.533 kJ/mol. Dislocations climbing over (Fe, Cr)(23)C-6 are observed, indicating that dislocation climbing is the main mechanism of creep deformation. Additionally, precipitation strengthening contributes to the creep behavior. Temperature, rather than stress, is found to be the main factor affecting recovery and recrystallization during creep deformation. Numerous voids are observed around the precipitates, and the fracture surface exhibits many dimples, suggesting a transgranular ductile fracture mechanism for creep fracture.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Engineering, Mechanical
Pei-Shan Ding, Xiao-Tao Zheng
Summary: The creep-ratcheting behavior of advanced 9-12 % Cr ferritic steel at 600 degrees C under different peak holding times was investigated, and a corresponding creep-ratcheting constitutive model was developed. Results showed that the anelastic strain remains relatively constant for different holding times, but decreases rapidly during the last several cycles. Moreover, the study observed the behavior of primary creep regeneration during repeated loading and unloading, which remains almost the same with increasing number of cycles.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
Jipeng Wang, Li Guo, Jinru Luo, Jiangfeng Song, Yan Shi, Chang'an Chen
Summary: This study investigates the evolution processes and characteristics of dislocation loops in HR3 steel under irradiation at different temperatures. The results show that irradiated samples at higher temperatures have larger average size and lower density of dislocation loops. The pre-existing dislocation lines have a significant impact on the density and Burgers vector of dislocation loops.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Wan Zhu, Zeyue Zhang, Dijun Long, Huijun Li, Liming Yu
Summary: In this study, the creep deformation behavior, microstructure evolution, and damage mechanism of Super304H oxide dispersion strengthened (ODS) steel at 650°C were systematically investigated. The creep behavior of the ODS steel was explained by a dislocation creep deformation mechanism. Interrupted creep experiments were conducted at 100 MPa to study the microstructure evolution during long-term creep deformation. The development of cavities around M23C6 phases and grain boundaries led to significant cracks and fracture of the steel during the second creep stage.
Article
Materials Science, Multidisciplinary
Y. Liu, K. Zweiacker, C. Liu, J. T. McKeown, J. M. K. Wiezorek
Summary: The evolution of rapid solidification microstructure and solidification interface velocity of hypereutectic Al-20at.%Cu alloy after laser melting has been studied experimentally. It was found that the formation of microstructure was dominated by eutectic, alpha-cell, and banded morphology grains, and the growth modes changed with increasing interface velocity.
Article
Materials Science, Multidisciplinary
Bharat Gwalani, Julian Escobar, Miao Song, Jonova Thomas, Joshua Silverstein, Andrew Chihpin Chuang, Dileep Singh, Michael P. Brady, Yukinori Yamamoto, Thomas R. Watkins, Arun Devaraj
Summary: Castable alumina forming austenitic alloys exhibit superior creep life and oxidation resistance at high temperatures. This study reveals the mechanism behind the enhanced creep performance of these alloys by suppressing primary carbide formation and offers a promising alloy design strategy for high-temperature applications.
Article
Materials Science, Multidisciplinary
Jian Song, Qi Zhang, Songsong Yao, Kunming Yang, Houyu Ma, Jiamiao Ni, Boan Zhong, Yue Liu, Jian Wang, Tongxiang Fan
Summary: Recent studies have shown that achieving an atomically flat surface for metals can greatly improve their oxidation resistance and enhance their electronic-optical applications. Researchers have explored the use of graphene as a covering layer to achieve atomically flat surfaces. They found that high-temperature deposited graphene on copper surfaces formed mono-atomic steps, while annealed copper and transferred graphene on copper interfaces formed multi-atomic steps.
Article
Materials Science, Multidisciplinary
Jennifer A. Glerum, Jon-Erik Mogonye, David C. Dunand
Summary: Elemental powders of Al, Ti, Sc, and Zr are blended and processed via laser powder-bed fusion to create binary and ternary alloys. The microstructural analysis and mechanical testing show that the addition of Ti results in the formation of primary precipitates, while the addition of Sc and Zr leads to the formation of fine grain bands. The Al-0.25Ti-0.25Zr alloy exhibits comparable strain rates to Al-0.5Zr at low stresses, but significantly higher strain rates at higher stresses during compressive creep testing. Finite element modeling suggests that the connectivity of coarse and fine grain regions is a critical factor affecting the creep resistance of the alloys.
Article
Materials Science, Multidisciplinary
P. Jannotti, B. C. Hornbuckle, J. T. Lloyd, N. Lorenzo, M. Aniska, T. L. Luckenbaugh, A. J. Roberts, A. Giri, K. A. Darling
Summary: This work characterizes the thermo-mechanical behavior of bulk nanocrystalline Cu-Ta alloys under extreme conditions. The experiments reveal that the alloys exhibit unique mechanical properties, behaving differently from conventional nanocrystalline Cu. They do not undergo grain coarsening during extrusion and exhibit behavior similar to coarse-grained Cu.
Article
Materials Science, Multidisciplinary
Yiqing Wei, Jingwei Li, Daliang Zhang, Bin Zhang, Zizhen Zhou, Guang Han, Guoyu Wang, Carmelo Prestipino, Pierric Lemoine, Emmanuel Guilmeau, Xu Lu, Xiaoyuan Zhou
Summary: This study proposes a new strategy to modify microstructure by phase regulation, which can simultaneously enhance carrier mobility and reduce lattice thermal conductivity. The addition of Cu in layered SnSe2 induces a phase transition that leads to increased grain size and reduced stacking fault density, resulting in improved carrier mobility and lower lattice thermal conductivity.
Article
Materials Science, Multidisciplinary
Jia Chen, Zhengyu Zhang, Eitan Hershkovitz, Jonathan Poplawsky, Raja Shekar Bhupal Dandu, Chang-Yu Hung, Wenbo Wang, Yi Yao, Lin Li, Hongliang Xin, Honggyu Kim, Wenjun Cai
Summary: In this study, the structural origin of the pH-dependent repassivation mechanisms in multi-principal element alloys (MPEA) was investigated using surface characterization and computational simulations. It was found that selective oxidation in acidic to neutral solutions leads to enhanced nickel enrichment on the surface, resulting in reduced repassivation capability and corrosion resistance.
Article
Materials Science, Multidisciplinary
X. Y. Xu, C. P. Huang, H. Y. Wang, Y. Z. Li, M. X. Huang
Summary: The limited slip systems of magnesium (Mg) and its alloys hinder their wide applications. By conducting tensile straining experiments, researchers discovered a rate-dependent transition in the dislocation mechanisms of Mg alloys. At high strain rates, glissile dislocations dominate, while easy-glide dislocations dominate at low strain rates. Abundant glissile dislocations do not necessarily improve ductility.
Article
Materials Science, Multidisciplinary
M. S. Szczerba, M. J. Szczerba
Summary: Inverse temperature dependences of the detwinning stress were observed in face-centered cubic deformation twins in Cu-8at.%Al alloy. The detwinning stress increased with temperature when the pi detwinning mode was involved, but decreased when the pi/3 mode was involved. The dual effect of temperature on the detwinning stress was due to the reduction of internal stresses pre-existing within the deformation twins. The complete reduction of internal stresses at about 530 degrees C led to the equivalence of the critical stresses of different detwinning modes and a decrease in the yield stress anisotropy of the twin/matrix structure.
Article
Materials Science, Multidisciplinary
Taowen Dong, Tingting Qin, Wei Zhang, Yaowen Zhang, Zhuoran Feng, Yuxiang Gao, Zhongyu Pan, Zixiang Xia, Yan Wang, Chunming Yang, Peng Wang, Weitao Zheng
Summary: The interaction between the electrode and the electric double layer (EDL) significantly influences the energy storage mechanism. By studying the popular alpha-Fe2O3 electrode and the EDL interaction, we find that the energy storage mechanism of the electrode can be controlled by modulating the EDL.
Article
Materials Science, Multidisciplinary
Matthew R. Barnett, Jun Wang, Sitarama R. Kada, Alban de Vaucorbeil, Andrew Stevenson, Marc Fivel, Peter A. Lynch
Summary: The elastic-plastic transition in magnesium alloy Mg-4.5Zn exhibits bursts of deformation, which are characterized by sudden changes in grain orientation. These bursts occur in a coordinated manner among nearby grains, with the highest burst rate observed at the onset of full plasticity. The most significant burst events are associated with twinning, supported by the observation of twinned structures using electron microscopy. The bursts are often preceded and followed by a stasis in peak movement, indicating a certain "birth size" for twins upon formation and subsequent growth at a later stage.
Article
Materials Science, Multidisciplinary
Vaidehi Menon, Sambit Das, Vikram Gavini, Liang Qi
Summary: Understanding solute segregation thermodynamics is crucial for investigating grain boundary properties. The spectral approach and thermodynamic integration methods can be used to predict solute segregation behavior at grain boundaries and compare with experimental observations, thus aiding in alloy design and performance control.
Article
Materials Science, Multidisciplinary
Feiyu Qin, Lei Hu, Yingcai Zhu, Yuki Sakai, Shogo Kawaguchi, Akihiko Machida, Tetsu Watanuki, Yue-Wen Fang, Jun Sun, Xiangdong Ding, Masaki Azuma
Summary: This study reports on the negative and zero thermal expansion properties of Cd2Re2O7 and Cd1.95Ni0.05Re2O7 materials, along with their ultra-low thermal conductivity. Through investigations of their structures and phonon calculations, the synergistic effect of local structure distortion and soft phonons is revealed as the key to achieving these distinctive properties.
Article
Materials Science, Multidisciplinary
Thomas Beerli, Christian C. Roth, Dirk Mohr
Summary: A novel testing system for miniature specimens is designed to characterize the plastic response of materials for which conventional full-size specimens cannot be extracted. The system has an automated operation process, which reduces the damage to specimens caused by manual handling and improves the stability of the test results. The experiments show that the miniature specimens extracted from stainless steel and aluminum have high reproducibility, and the results are consistent with those of conventional-sized specimens. A correction procedure is provided to consider the influence of surface roughness and heat-affected zone caused by wire EDM.
Article
Materials Science, Multidisciplinary
Rani Mary Joy, Paulius Pobedinskas, Nina Baule, Shengyuan Bai, Daen Jannis, Nicolas Gauquelin, Marie-Amandine Pinault-Thaury, Francois Jomard, Kamatchi Jothiramalingam Sankaran, Rozita Rouzbahani, Fernando Lloret, Derese Desta, Jan D'Haen, Johan Verbeeck, Michael Frank Becker, Ken Haenen
Summary: This study investigates the influence of film microstructure and composition on the Young's modulus and residual stress in nanocrystalline diamond thin films. The results provide insights into the mechanical properties and intrinsic stress sources of these films, and demonstrate the potential for producing high-quality nanocrystalline diamond films under certain conditions.