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Oxidation behavior of multiphase Mo_5SiB_2 (T2)-based alloys at high temperatures

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中国有色金属学会会刊：英文版 2007年第6期17卷 1242-1247页

作者：王方单爱党董显平吴建生 Key Laboratory of Ministry of Education for high temperature materials and Testing School of Materials Science and EngineeringShang hai Jiao Tong University

Two Mo5SiB2 (T2)-based alloys with nominal compositions of Mo-12.5Si-25B and Mo-14Si-28B (molar fraction, %) were prepared in an arc-melting furnace, and their oxidation kinetics from 1 000 to 1 300 ℃ were studied. The microstructures of the alloys were characterized by X-ray diffractometry(XRD) and scanning electron microscopy(SEM) with energy dispersive spectroscopy (EDS). The oxide scales of both alloys oxidized at 1 200 ℃ for 10 min, 2 h and 100 h were investigated by surface XRD and cross-sectional SEM-EDS. The results show that the matrix of both alloys consists of T2. The dispersions of Mo-12.5Si-25B alloy are Mo and Mo3Si, and the dispersions of Mo-14Si-28B alloy are Mo5Si3 (T1) and MoB. The cyclic oxidation kinetics data exhibit initial rapid mass loss followed by slow mass loss. The mass loss of Mo-12.5Si-25B alloy is much faster than that of Mo-14Si-28B alloy at 1 200 and 1 300 ℃. For 10 min exposure, both alloys form irregular and porous thin scale. For 2 h exposure, Mo-12.5Si-25B alloy forms irregular thin scale and the scale contains large cracks, and Mo-14Si-28B alloy forms sound and continuous scale. For 100 h exposure, Mo-12.5Si-25B and Mo-14Si-28B alloys form sound and continuous scale about 50-75 μm and 40-45 μm in thickness, respectively. The better oxidation resistance of Mo-14Si-28B alloy is due to a sound and continuous B-SiO2 layer formation in the early stage of oxidation.

关键词： MosSiB2合金氧化作用扩散金属间化合微观结构

A low redox potential and long life organic anode material for sodium-ion batteries

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Journal of energy Chemistry 2025年第01期 557-564页

作者： Zhi Li Yang Wei Kang Zhou Xin Huang Xing Zhou Jie Xu Taoyi Kong Junwei Lucas Bao Xiaoli Dong Yonggang Wang Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative materials Institute of New Energy Collaborative Innovation Center of Chemistry for Energy Materials (iChEM) Fudan University Department of Chemistry Boston College School of materials Science and Engineering Anhui University of Technology

Sodium-ion batteries （SIBs） with organic electrodes are an emerging research direction due to the sustainability of organic materials based on elements like C,H,O,and sodium ***,organic electrode materials for SIBs are mainly used as cathodes because of their relatively high redox potentials（>1 V）.Organic electrodes with low redox potential that can be used as anode are ***,a novel organic anode material （tetrasodium 1,4,5,8-naphthalenetetracarboxylate,Na4TDC） has been developed with low redox potential （high capacity of 208 mAh/g and an average decay rate of merely 0.022%per ***,the Na4TDC-hard carbon composite can further acquire improved capacity and cycling stability for 1200 cycles even with a high mass loading of up to 20 mg *** pairing with a thick Na3V2（PO4）3cathode (20.6 mg cm-2),the as-fabricated full cell exhibited high operating voltage （2.8 V）,excellent rate performance and cycling stability with a high capacity retention of 88.7% after 200 cycles,well highlighting the Na4TDC anode material for SIBs.

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Hot corrosion behavior of the spray-formed nickel-based superalloy

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Chinese Physics B 2016年第12期25卷 462-467页

作者：夏敏谷天赋贾崇林葛昌纯 School of materials Science and Engineering University of Science and Technology Beijing Science and Technology on Advanced high temperature Structural materials Laboratory Beijing Institute of Aeronautical Materials

An investigation of low temperature hot corrosion is carried out on a spray-formed nickel-based superalloy FGH100 pre-coated with Na2SO4-NaC1 at 700 ℃ for 100 h. Mass gain measurement, x-ray diffraction, scanning electron mi- croscopy, and energy dispersive x-ray spectroscopy are used to study the corrosion behavior. Results reveal that corrosion behavior follows a sequence, that is, first rapidly proceeding, then gradually slowing down, and finally forming an outer layer composed of different types of oxides and an inner layer mainly comprised of sulfides. In-depth analysis reveals that the hot corrosion of FGH100 is a combined effect of oxidation-sulfidation and transfer of oxides.

关键词： superalloy, molten salts hot corrosion, oxidation

Constraints on holographic QCD phase transitions from PTA observations

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 71-78页

作者： Song He Li Li Sai Wang Shao-Jiang Wang center for Theoretical Physics and College of Physics Jilin University School of Physical Science and Technology Ningbo University Max Planck Institute for Gravitational Physics (Albert Einstein Institute) CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences (UCAS) School of Physical Sciences University of Chinese Academy of Sciences (UCAS) Theoretical Physics Division Institute of High Energy Physics Chinese Academy of Sciences

The underlying physics of QCD phase transition in the early Universe remains largely unknown due to its strong-coupling nature during the quark-gluon plasma/hadron gas transition, yet a holographic model has been proposed to quantitatively fit the lattice QCD data while with its duration of the first-order phase transition(FoPT) left undetermined. At specific baryon chemical potential, the first-order QCD phase transition agrees with the observational constraint of baryon asymmetry. It, therefore, provides a scenario for phase transition gravitational waves(GWs) within the standard model of particle physics. If these background GWs could contribute dominantly to the recently claimed common-spectrum red noise from pulsar timing array(PTA) observations, the duration of this FoPT can be well constrained, and the associated primordial black holes are still allowed by current observations.

关键词： pulsar timing array QCD phase transition gravitational waves primordial black holes

Effect of humidity on microstructure and properties of YBCO film prepared by TFA-MOD method

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Journal of Rare Earths 2009年第3期27卷 486-489页

作者：王连红李弢古宏伟 The Key Laboratory of high temperature Gas Dynamics Institute of MechanicsChinese Academy of Sciences Superconducting materials Research center General Research Institute for Non-ferrous Metals

Epitaxial YBCO superconducting films were deposited on the single crystal LaAlO3 （001） substrate by metal organic deposition method. All YBCO films were fired at 820 ℃ in humidity range of 2.6%-19.7% atmosphere. Microstructure of YBCO thin films was analyzed by means of X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Superconducting properties of YBCO films were measured by four-probe method. XRD results showed that the second phase （such as BaF2）and a-axis-oriented grains existed in the films prepared at 2.6% humidity condition; a-axis-oriented grains increased in the film prepared at higher than 4.2% humidity condition; almost pure c-axias-oriented grains existed in the films fired at 4.2% humidity condition. Morphologies of the YBCO films showed that all films had a smooth and crack-free surface. YBCO film prepared at 4.2% humidity condition showed Jc value of 3.3 MA/cm^2 at 77 K in self-field.

关键词： YBCO TFA-MOD coated conductor superconductivity rare earths

Low cycle fatigue behavior of micro-grain casting K4169 superalloy at room temperature

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Progress in Natural Science:materials International 2022年第6期32卷 693-699页

作者： Rui Liu Xitao Wang Pinpin Hu Chengbo Xiao Jinshan He Collaborative Innovation center of Steel Technology University of Science and Technology Beijing Shandong Provincial Key Laboratory for high Strength Lightweight Metallic materials Advanced Materials Institute Qilu University of Technology (Shandong Academy of Science) Science and Technology on Advanced high temperature Structural materials Laboratory AECC Beijing Institute of Aeronautical Materials

The strain-controlled low cycle fatigue tests were carried out at 298 K for the newly developed micro-grain casting K4169 superalloy,and the cyclic stress response,deformation and fracture behaviors of the alloy were *** results show that the fatigue life of the alloy was increased by more than two times compared with other casting K4169 *** can be partly attributed to grain refinement impeding crack initiation and *** the strain amplitude was in plastic range(Δεt/2≥ 0.5%),the alloy displayed a short period of initial cyclic stability followed by cyclic softening to *** observing dislocation configurations,only a few dislocations moved around grain boundaries at initial cycles,leading to short cyclic ***,dislocations in the slip bands cut γ" phase continuously leading to cyclic *** the strain amplitude was in elastic range(Δεt/2 ≤ 0.4%),the alloy exhibited elastic deformation and the peak stress kept *** addition,the crack initiation site changed from the MC carbides to the persistent slip bands on surface with increasing strain amplitudes.

关键词： Micro-grain cast K4169 Low-cycle fatigue Cyclic softening Slip bands

Steady-State Creep Behavior of Super304H Austenitic Steel at Elevated temperatures

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Acta Metallurgica Sinica(English Letters) 2015年第11期28卷 1336-1343页

作者： Ping Ou Long Li Xing-Fei Xie Jian Sun Shanghai Key Laboratory of Advanced high-temperature materials and Precision Forming School of Materials Science and EngineeringShanghai Jiaotong University School of materials Science and Engineering Jiangxi University of Science and Technology

Creep behavior of Super304H austenitic steel has been investigated at elevated temperatures of 923-973 K and at applied stress of 190-210 MPa. The results show that the apparent stress exponent and activation energy in the creep deformation range from 16.2 to 27.4 and from 602.1 to 769.3 kJ/mol at different temperatures, respectively. These high values imply the presence of a threshold stress due to an interaction between the dislocations and Cu-rich precipitates during creep deformation. The creep mechanism is associated with the dislocation climbing governed by the matrix lattice diffusion. The origin of the threshold stress is mainly attributed to the coherency strain induced in the matrix by Cu-rich precipitates. The theoretically estimated threshold stresses from Cu-rich precipitates agree reasonably with the experi- mental results.

关键词： Super304H steel Cu-rich precipitate Creep Threshold stress

Effects of Ru on the microstructure and phase stability of a single crystal superalloy

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International Journal of Minerals,Metallurgy and materials 2012年第11期19卷 1004-1009页

作者： Zhen-xue Shi Jia-rong Li Shi-zhong Liu Science and Technology on Advanced high temperature Structural materials Laboratory Beijing Institute of Aeronautical MaterialsBeijing 100095China

Two experimental single crystal superalloys, the Ru-free alloy and the Ru-containing alloy with [001 ] orientation, were cast in a directionally solidified furnace, while other alloying element contents were kept unchanged. The effects of Ru on the microstructure and phase stability of the single crystal superalloy were investigated, y＇ directional coarsening and rafting were observed in the Ru-free alloy and Ru-containing alloy after long-term aging at 1070~C for 800 h. Needle-shaped o topologically close packed （TCP） phases precipitated and grew along the fixed direction in both the alloys. The precipitating rate and volume fraction of TCP phases decreased significantly by adding Ru. The compositions ofy and y＇ phases measured using an energy-dispersive X-ray spectroscope （EDS） in transmission electron microscopy （TEM） analysis showed that the addition of Ru lessened the partition ratio of TCP forming elements, Re, W and Mo, and decreased the satu- ration degrees of these elements in y phase, which can enable the Ru-containing alloy to be more resistant to the formation of TCP phases. It is indicated that the addition of Ru to the Ni-based single crystal superalloy with high content of the refractory alloying element can enhance phase stability.

关键词： superalloys nickel alloys single crystals ruthenium microstructure phase stability

Composite electronic orders induced by orbital Kondo effect

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Science Bulletin 2016年第20期61卷 1563-1582页

作者： Yoshio Kuramoto Institute of materials Structure Science High Energy Accelerator Research Organization

In a large number of rare-earth and actinide systems,Kondo effect tends to suppress magnetic orders by making the spin singlet between localized and conduction electron *** the presence of orbital degrees of freedom,however,there emerge exotic electronic orders induced by Kondo *** orbital Kondo effect can collectively make diagonal and off-diagonal(superconducting) *** the particle-hole symmetry in conduction bands,these orders are all degenerate,forming a macroscopic SO(5) *** paper discusses recent theoretical development on these electronic orders which are relevant to Pr^(3+) and U^(4+) systems with even number of f electrons per *** the superconducting order,each conduction–electron pair is coupled with local degrees of freedom,forming a composite entity with a staggered spatial *** quasi-particle spectrum is best interpreted as virtual hybridization with resonant states at the Fermi *** order parameter for URu_2Si_2 in the hidden order state is discussed in the context of composite *** discussed are related issues such as homogeneous odd-frequency pairing and SO(5) theory for hightemperature superconductors.

关键词： Orbital Kondo effect Composite orderOdd-frequency order S0(5) symmetry -Non-Kramers states