摘要：
Directionally solidified gas turbine blades are wildly used in land-based industrial gas turbines for power generation. During long-term service, the harsh service environment causes microstructural and mechanical deterioration of the blades. In order to increase usage and save costs, this study analyzed the microstructure damage in different sections of the blade. Meanwhile, this investigation discussed the optimum rejuvenation heat treatment parameter and applied it to the serviced blade for the lifetime extension. The microstructural analysis indicated that the appropriate solution temperature for the serviced blade is 1205 degrees C. Furthermore, the microstructure of the degraded blade was effectively recovered including the gamma ' dissolution and reprecipitation with the cubic shape, tertiary gamma ' reprecipitation in gamma matrix, part of film-like M23C6 redissolution and dislocation networks were eliminated after rejuvenation heat treatment. In addition, the stress rupture lifetime and the tensile and yield strength were effectively improved by rejuvenation heat treatment.(c) 2023 Elsevier B.V. All rights reserved.
作者机构：
[Ding, Junwei; Ji, Xiaoyan; Hu, Haiman; Li, Jiajia; Ji, XY] Lulea Univ Technol, Div Energy Sci, Energy Engn, S-97187 Lulea, Sweden.;[Luo, Shuangjiang; Li, Jiajia; Zhang, Haitao; Fang, Wenhao] Chinese Acad Sci, Inst Proc Engn, CAS Key Lab Green Proc & Engn, Beijing Key Lab Ion Liquids Clean Proc, Beijing 100190, Peoples R China.;[Yuan, Du] Changsha Univ Sci & Technol, Coll Mat Sci & Engn, 960, 2nd Sect,Wanjiali RD S, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Ji, XY ] L;[Zhang, HT ] C;Lulea Univ Technol, Div Energy Sci, Energy Engn, S-97187 Lulea, Sweden.;Chinese Acad Sci, Inst Proc Engn, CAS Key Lab Green Proc & Engn, Beijing Key Lab Ion Liquids Clean Proc, Beijing 100190, Peoples R China.
关键词：
chemical bonding;fluorine;lithium metal batteries;solid-electrolyte interphase
摘要：
LiF-rich solid-electrolyte-interphase (SEI) can suppress the formation of lithium dendrites and promote the reversible operation of lithium metal batteries. Regulating the composition of naturally formed SEI is an effective strategy, while understanding the impact and role of fluorine (F)-based Li-salts on the SEI characteristics is unavailable. Herein, LiFSI, LiTFSI, and LiPFSI are selected to prepare solid polymer electrolytes (SPEs) with poly(ethylene oxide) and polyimide, investigating the effects of molecular size, F contents and chemical structures (F-connecting bonds) of Li-salts and revealing the formation of LiF in the SEI. It is shown that the F-connecting bond is more significant than the molecular size and F element contents, and thus the performances of cells using LiPFSI are slightly better than LiTFSI and much better than LiFSI. The SPE containing LiPFSI can generate a high amount of LiF, and SPEs containing LiPFSI and LiTFSI can generate Li3N, while there is no Li3N production in the SEI for the SPE containing LiFSI. The preferential breakage bonds in LiPFSI are related to its position to Li anode, where Li-metal as the anode is important in forming LiF, and consequently the LiPFSI reduction mechanism is proposed. This study will boost other energy storage systems beyond Li-ion chemistries.
关键词：
Al alloys;Gradient microstructure;Precipitation;Laser remelting;Strength-ductility synergy
摘要：
Titanium (Ti) is generally known for its limited solid solubility and used as grain refiner in Al-based alloys, accelerating heterogeneous alpha-Al nucleation during solidification. In this study, a newly developed surface modification of pure Al followed by sputtering Ti film (similar to 1 mu m) and subsequent laser remelting has been proposed. Gradient structural features in both grain size and chemical composition have been accomplished in the top surface layer (<10 mu m), showing three typical domains with different grain morphology and Al3Ti nanoprecipitates. The simultaneous increase in strength and ductility is attributed to the strong dislocation-precipitate interaction inside gradient nano-grained top-surface layer, which has been confirmed by the partially dissolved Al3Ti nanoprecipitates induced by deformation. The findings in this work provide a new routine for upgrading mechanical properties through the manipulation of both grain- and chemical-gradients.
摘要：
A neutral aqueous single‐molecule redox‐targeting (SMRT)‐based Prussian blue (PB)−Fe/S flow battery was demonstrated. Especially, the energy density of a battery based on [Fe(CN)6]3−/4−‐containing catholyte is increased to 92.8 Wh L−1. Moreover, the PB−Fe/S flow battery exhibits outstanding performance with long cycle life over 7000 cycles (4500 h), and the chemical cost of the PB−Fe/S full cell is as low as 19.26 $ kWh−1. Abstract Neutral aqueous flow batteries with common traits of the redox flow batteries, such as the independence of energy and power, scalability and operational flexibility, and additional merits of outstanding safety and low corrosivity show great promise for storing massive electrical energy from solar and wind energy. Particularly, the ferricyanide/ferrocyanide ([Fe(CN)6]3−/4−) couple has been intensively employed as redox mediator to store energy in the catholyte ascribed to its abundance, low corrosivity, remarkable redox reversibility and stability. However, the low energy density arising from poor solubility of [Fe(CN)6]3−/4− restricts their commercial applications for energy storage systems. In this study, the practical energy density of a [Fe(CN)6]3−/4−‐based catholyte is significantly boosted from 10.5 to 92.8 Wh L−1 by combining the counter‐ion effect and the single‐molecule redox‐targeting (SMRT) reactions between [Fe(CN)6]3−/4− and Prussian blue (Fe4[Fe(CN)6]3, PB)/Prussian white (PW). Paired with concentrated K2S anolyte, we demonstrate a neutral aqueous SMRT‐based PB−Fe/S flow battery with ultra‐long lifespan over 7000 cycles (4500 h) and ultra‐low chemical cost of electrolytes in the cell as 19.26 $ kWh−1. Remarkably, under the influences of SMRT reactions in the presence of PB granules in the catholyte, the capacity after 7000 cycles of the PB−Fe/S flow battery is 181.8 % of the initial capacity without PB.
摘要：
Layered Ni-rich transition metal oxides (LiNixCoyMnzO2, x + y + z = 1, NCM) are regarded as promising cathodes for high-energy Li-ion batteries, due to merits of large capacity and low cost. However, the formed microcracks during cycling can lead to severe structural degradation, rapidly deteriorating properties of NCM cathode. To solve this problem, an enhanced mechanical strength strategy triggered by regulating the grain size of precursor has been successfully proposed, which is aimed at improving the structural stability of NCM cathode. It is found that NCM cathode featured with small grain size (NCM-S) exhibits a strong mechanical property for hindering structural deterioration. Detailedly, the strong external compression rupture strength triggered by grain size effect and decreased internal stress originating from mitigated H2-H3 phase transition are both beneficial for synergistically suppressing the generation of microcracks. Benefiting from the unique architecture, the NCM-S cathode delivers a remarkable initial discharge capacity of 192.6 mAh g(-1) at 0.1C and excellent capacity retention of 82.8 % after 300 cycles at 1C. This work powerfully provides a mechanistic perspective based on the regulating precursor grain size for impeding the structure collapse, which is beneficial for purposefully engineering the high-performance Ni-rich cathodes in electric vehicles.
关键词：
aluminum batteries;organic cathode;molecular design;sulfurization;density functional theory
摘要：
Thispaper reports SPTCDA cathode for green and sustainablealuminum organic battery. Aluminumbatteries with aluminum as the anode and organic materialsas the cathode have continuously drawn considerable attention becauseof their high theoretical energy density, natural abundance, and environmentallybenign nature. Herein, we have done an elaborate design work on thebasis of & pi;-& pi; conjugated organic molecule PTCDAby a molecular engineering strategy. Introducing a sulfur atom toreplace the H atom in the aromatic ring of the PTCDA molecule to formSPTCDA (sulfurized PTCDA) with p-& pi; conjugated systemcan reduce the energy level of the molecule. In addition, the extensionof the conjugated system makes the electrons more delocalized, whichis beneficial to the improvement of the conductivity of SPTCDA. Experimentalresults show that compared with pristine PTCDA, SPTCDA has a morestable structure and better cycle performance, rate capability, andcoulombic efficiency, as well as a higher discharge voltage plateau.To further understand the electronic structure, operating voltage,and correct redox mechanism, density functional theory (DFT) calculationswere performed for PTCDA and SPTCDA. The diffusion behavior of ionson the electrode surface was also discussed. This work reveals animportant molecular structure design strategy for a carbonyl cathode,in order to break the application limitations of this electrode materialon aluminum organic batteries.
通讯机构：
[Jinhui Huang] C;College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China<&wdkj&>Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, Hunan, 410082, China
关键词：
3D framework;Biofouling;Electrospun membrane;Membrane bioreactor;Structure enhancing;quorum quenching
摘要：
Bacterial quorum quenching (QQ) is an effective strategy for controlling biofouling in membrane bioreactor (MBR) by interfering the releasing and degradation of signal molecules during quorum sensing (QS) process. However, due to the framework feature of QQ media, the maintenance of QQ activity and the restriction of mass transfer threshold, it has been difficult to design a more stable and better performing structure in a long period of time. In this research, electrospun fiber coated hydrogel QQ beads (QQ-ECHB) were fabricated by using electrospun nanofiber coated hydrogel to strengthen layers of QQ carriers for the first time. The robust porous PVDF 3D nanofiber membrane was coated on the surface of millimeter-scale QQ hydrogel beads. Biocompatible hydrogel entrapping quorum quenching bacteria (sp.BH4) was employed as the core of the QQ-ECHB. In MBR with the addition of QQ-ECHB, the time to reach transmembrane pressure (TMP) of 40 kPa was 4 times longer than conventional MBR. The robust coating and porous microstructure of QQ-ECHB contributed to keeping a lasting QQ activity and stable physical washing effect at a very low dosage (10g beads/5L MBR). Physical stability and environmental-tolerance tests also verified that the carrier can maintain the structural strength and keep the core bacteria stable when suffering long-term cyclic compression and great fluctuations in sewage quality.
摘要：
Styrene/1,3-diene copolymers are widely used in rubber tires, adhesives, waterproof materials, automotive parts and others. However, their oil resistance, compatibility with polar materials, and poor adhesion limit their applications. Polarization modification strategy can further expand the application field of such materials. In this paper, a series of strictly alternating copolymers were synthesized in cyclohexane via living and controlled anionic alternating copolymerization of styrene derivatives (including styrene (ST), p-methylstyrene (MST), p-tert-butylstyrene (TBS), and 1,1-diphenylethylene (DPE)) with 1,3-pentadiene (PD) using n-BuLi initiator. The above-mentioned alternating copolymers were epoxidized in cycloamyl methyl ether (CPME, green solvent) using m-Chloroperoxybenzoic acid (m-CPBA) as the oxygen source. The H-1 NMR and FTIR results showed that the degree of epoxidation (DE) of the alternating copolymers was controllable and the cross-linking gels can be avoided (determined by solubility experiment), and the DE of nearly 100% could be achieved by optimizing processes. As for these PD-based alternating copolymers, the type of substituents on rigid benzene rings has a certain impact on the epoxidation rate as well as the DE. DSC results showed that not only the high steric hindrance groups in polymer side chains but also the epoxidation strategy can greatly improve the heat resistance of the product.
摘要：
A novel functional terpolymer was prepared by one-pot radical terpolymerization of cis-1,3-pentadiene (CP), maleic anhydride (MAH), and styrene (St) using Azobisisobutyronitrile (AIBN) and Benzoyl peroxide (BPO) as initiators in Tetrahydrofuran (THF) solvent. Although the charge transfer complexes between MAH and two electron-rich comnomers have low concentrations in the feed (K-eq = 0.71 L/mol at 25 degrees C in THF), the two complexes are more reactive than the free monomers by kinetic analysis. And all attempts to homopolymerize the single monomers and to copolymerize the two donor-monomers St/CP under our given conditions failed. Therefore, Such terpolymerization can be described as "complex" mechanisms in the state of near-binary copolymerization of [MAHSt] and [MAHCP] complexes, and the constants of complex-radical terpolymerization, complex formation, and some kinetic parameters for the monomer systems were studied by Ultraviolet spectrum (UV), Nuclear magnetic resonance (NMR), Kelen-Tudos and Fineman-Ross methods, respectively. And as the similar copolymerization reactivity of the two intermediates, the terpolymer displayed the characteristics of "gradient" distribution with high molecular weight M(n)s (50-95 kg/mol) and adjustable T(g)s. Their terpolymerization resulted in a (MAH-alt-St)-ran-(MAH-alt-CP) sequence as a consequence of the selective alternating copolymerization between MAH and CP/St, the lack of copolymerization between St and CP, as well as no homopolymerization of MAH or St or CP under our conditions.
通讯作者：
Dr. Tao Dong<&wdkj&>Prof. Haitao Zhang<&wdkj&>Dr. Tao Dong Dr. Tao Dong Dr. Tao Dong<&wdkj&>Prof. Haitao Zhang Prof. Haitao Zhang Prof. Haitao Zhang
作者机构：
[Dr. Tao Dong; Jiaxin Liu; Dr. Yingyue Cui; Dr. Tao Dong Dr. Tao Dong Dr. Tao Dong; Jiaxin Liu Jiaxin Liu Jiaxin Liu; Dr. Yingyue Cui Dr. Yingyue Cui Dr. Yingyue Cui] Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190 P. R. China;School of Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou, 450002 P. R. China;[Dr. Du Yuan; Dr. Du Yuan Dr. Du Yuan Dr. Du Yuan] College of Materials Science and Engineering, Changsha University of Science and Technology, 960, 2nd Section, Changsha, Hunan, 410004 P. R. China;Henan Key Laboratory of Energy Storage Materials and Processes, Zhengzhou Institute of Emerging Industrial Technology, Zhengzhou, 450003 P. R. China;[Xuedi Yuan; Haotian Dong; Xuedi Yuan Xuedi Yuan Xuedi Yuan; Haotian Dong Haotian Dong Haotian Dong] Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190 P. R. China<&wdkj&>School of Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou, 450002 P. R. China
通讯机构：
[Dr. Tao Dong; Prof. Haitao Zhang; Dr. Tao Dong Dr. Tao Dong Dr. Tao Dong; Prof. Haitao Zhang Prof. Haitao Zhang Prof. Haitao Zhang] B;Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190 P. R. China<&wdkj&>Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190 P. R. China<&wdkj&>School of Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou, 450002 P. R. China<&wdkj&>Henan Key Laboratory of Energy Storage Materials and Processes, Zhengzhou Institute of Emerging Industrial Technology, Zhengzhou, 450003 P. R. China
摘要：
The practical implementation of high-voltage lithium-rich manganese oxide (LRMO) cathode is limited by the unanticipated electrolyte decomposition and dissolution of transition metal ions. The present study proposes a bi-affinity electrolyte formulation, wherein the sulfonyl group of ethyl vinyl sulfone (EVS) imparts a highly adsorptive nature to LRMO, while fluoroethylene carbonate (FEC) exhibits a reductive nature towards Li metal. This interface modulation strategy involves the synergistic use of EVS and FEC as additives to form robust interphase layers on the electrode. As-formed S-endorsed but LiF-assisted configuration cathode electrolyte interphase with a more dominant −SO2− component may promote the interface transport kinetics and prevent the dissolution of transition metal ions. Furthermore, the incorporation of S component into the solid electrolyte interphase and the reduction of its poorly conducting component can effectively inhibit the growth of lithium dendrites. Therefore, a 4.8 V LRMO/Li cell with optimized electrolyte may demonstrate a remarkable retention capacity of 97 % even after undergoing 300 cycles at 1 C.
期刊：
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing,2023年885:145559 ISSN：0921-5093
通讯作者：
Guo, ZH;Bai, L;Zhao, ZB
作者机构：
[Guo, Zhenghua; Jiang, Lihong; Liu, Zheng; Zhang, Yingrui; Guo, ZH] Nanchang Hangkong Univ, Sch Aeronaut Mfg Engn, Nanchang 330063, Jiangxi, Peoples R China.;[Zhang, Qi; Yang, Dezhu; Liu, Zheng] AECC Guizhou Honglin Aeroengine Control Technol Co, Guiyang 550009, Guizhou, Peoples R China.;[Liu, Zheng] Huazhong Univ Sci & Technol, State Key Lab Mat Proc & Die & Mould Technol, Wuhan 430074, Peoples R China.;[Bai, Lu] NanChang JiaoTong Inst, Nanchang 330100, Jiangxi, Peoples R China.;[Liu, Yujing] Changsha Univ Sci & Technol, Inst Met, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Zhao, ZB ] C;[Guo, ZH ; Bai, L ] N;Nanchang Hangkong Univ, Sch Aeronaut Mfg Engn, Nanchang 330063, Jiangxi, Peoples R China.;NanChang JiaoTong Inst, Nanchang 330100, Jiangxi, Peoples R China.;Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China.
关键词：
Ti-6Al-4V alloy;Electron beam directed energy deposition;alpha lamellae;Spatial orientation;Anisotropy
摘要：
Crystallographic texture of alloy can trigger anisotropic properties, which have been studied extensively. However, the effect of spatial orientation of grains on the mechanical properties, especially for additive manufactured metals with lamellar morphology has remained elusive. Herein, this work theoretically calculated the spatial and crystallographic orientations of a lath from the < 100 >(ss)//Z-axis (build direction) fiber texture, and investigate the relationship between the orientations of a lath and the deformation behaviors and mechanical properties of the Ti-6Al-4V alloy built via electron beam directed energy deposition (EB DED). Deformation features display the prismatic slip system of alpha lath that exists a smaller angle to the broad face of a lath showing a lower effective critical resolved shear stress (CRSS). This is because this prismatic slip system has a greater slip range when compares with other slip systems. Such deformation features, combined with the spatial orientation distribution characteristic of a lath that is induced by the < 100 >(ss)//Z-axis fiber texture, lead to strongly tensile anisotropy, specifically, the samples oriented 45(circle) and 67.5(circle) angles to z-axis present greater strengths but lower ductility, whereas the sample in the z-axis direction generally displays a minimum strength but a superb ductility. This finding is vital for providing an important theoretical basis for optimizing the consistency of mechanical properties of the additive manufactured a+ss dual phase titanium alloy.
作者机构：
[Liu, Zhengxin; Huang, Shenglei; Li, Xiaodong; Meng, Fanying; Guo, Lan; Zhou, Yinuo; Meng, FY; Han, Anjun; Liu, Wenzhu; Yang, Yuhao; Wang, Guangyuan; Jiang, Kai; Shi, Qiang; Li, Zhenfei; Liu, ZX; Shi, Jianhua; Zhang, Liping; Du, Junling; Zhang, LP] Chinese Acad Sci, Shanghai Inst Microsyst & Informat Technol, Res Ctr New Energy Technol, Shanghai, Peoples R China.;[Li, Xiaodong; Zhang, LP; Liu, Wenzhu; Jiang, Kai; Zhang, Liping] Univ Chinese Acad Sci, Beijing, Peoples R China.;[Liu, Yujing; Liu, Xiaochun; Liu, XC] Changsha Univ Sci & Technol, Inst Met, Coll Mat Sci & Engn, Changsha, Peoples R China.;[Yang, Ziqiang; Thoroddsen, Sigurdur] King Abdullah Univ Sci & Technol, Div Phys Sci & Engn, Thuwal, Saudi Arabia.;[Xu, Changqing] King Abdullah Univ Sci & Technol, Div Comp Elect & Math Sci & Engn, Thuwal, Saudi Arabia.
通讯机构：
[Zhang, LP ] U;[Liu, XC ; Liu, WZ; Di, ZF ; Meng, FY; Liu, ZX ; Zhang, LP] C;Chinese Acad Sci, Shanghai Inst Microsyst & Informat Technol, Res Ctr New Energy Technol, Shanghai, Peoples R China.;Univ Chinese Acad Sci, Beijing, Peoples R China.;Changsha Univ Sci & Technol, Inst Met, Coll Mat Sci & Engn, Changsha, Peoples R China.
摘要：
Flexible solar cells have a lot of market potential for application in photovoltaics integrated into buildings and wearable electronics because they are lightweight, shockproof and self-powered. Silicon solar cells have been successfully used in large power plants. However, despite the efforts made for more than 50 years, there has been no notable progress in the development of flexible silicon solar cells because of their rigidity1–4. Here we provide a strategy for fabricating large-scale, foldable silicon wafers and manufacturing flexible solar cells. A textured crystalline silicon wafer always starts to crack at the sharp channels between surface pyramids in the marginal region of the wafer. This fact enabled us to improve the flexibility of silicon wafers by blunting the pyramidal structure in the marginal regions. This edge-blunting technique enables commercial production of large-scale (>240 cm2), high-efficiency (>24%) silicon solar cells that can be rolled similarly to a sheet of paper. The cells retain 100% of their power conversion efficiency after 1,000 side-to-side bending cycles. After being assembled into large (>10,000 cm2) flexible modules, these cells retain 99.62% of their power after thermal cycling between −70 °C and 85 °C for 120 h. Furthermore, they retain 96.03% of their power after 20 min of exposure to air flow when attached to a soft gasbag, which models wind blowing during a violent storm. Modules of foldable crystalline silicon solar cells retain their power-conversion efficiency after being subjected to bending stress or exposure to air-flow simulations of a violent storm.
通讯机构：
[Liu, YR ] C;Changsha Univ Sci & Technol, Sch Traff & Transportat Engn, Changsha 410114, Peoples R China.
摘要：
Although there have been reports showing the modification effect of carbon nanomaterials on asphalt, there are few studies on whether carbon nanomaterials and polymers can have synergistic modification effects on asphalt. At the same time, the complex composition of asphalt makes it difficult to determine the interface mechanism between the modifier and the asphalt. In this study, graphene oxide (GO) and styrene–butadiene–styrene block copolymer (SBS) were selected as modifiers. A combined experimental and molecular simulation research method was used to study the synergistic modification effect and the interface mechanism between the modifier and the asphalt. The results show that the modification effect of GO/SBS incorporated into asphalt is significantly superior to that of GO or SBS incorporated individually and GO/SBS has a synergistic modification effect. Although the binding strength between SBS and asphalt is weak, the GO surface (GO (0 0 1)) can simultaneously bind with SBS and asphalt, increasing the binding strength of SBS and asphalt as well as promoting the dispersion of SBS in asphalt, so that GO/SBS shows a synergistic modification effect and improves properties such as low-temperature ductility, rheology and storage stability at macroscopic level. Intercalated and exfoliated structure can be formed between GO side (GO (0 1 0)) and asphalt, which improves the anti-aging properties of the asphalt. Physical bonding is the main interface binding for GO/SBS compound-modified asphalt. GO bonds to asphalt or SBS by hydrogen bonds and there are only dispersion forces between SBS and asphalt, resulting in a higher binding strength between GO and asphalt or SBS than between SBS and asphalt.
作者机构：
[Li, Yue] Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany. yue.li@mpie.de;[Dsouza, Raynol; Wei, Ye; Gong, Yilun; Zhou, Xuyang; Huber, Liam; Neugebauer, Jörg; Stephenson, Leigh T; Rao, Ziyuan; Han, Liuliu] Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany;[Wang, Zhangwei] State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083, China. z.wang@csu.edu.cn;[Liu, Xiaochun] Institute of Metals, College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, 410114, China;[Marek, Andreas; Colnaghi, Timoteo; Rampp, Markus] Max Planck Computing and Data Facility, Gießenbachstraße 2, 85748, Garching, Germany
通讯机构：
[Li, Yue; Gault, Baptiste] M;[Wang, Zhangwei] S;Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany. yue.;State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083, China. z.;Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany. b.
摘要：
Chemical short-range order (CSRO) refers to atoms of specific elements self-organising within a disordered crystalline matrix to form particular atomic neighbourhoods. CSRO is typically characterized indirectly, using volume-averaged or through projection microscopy techniques that fail to capture the three-dimensional atomistic architectures. Here, we present a machine-learning enhanced approach to break the inherent resolution limits of atom probe tomography enabling three-dimensional imaging of multiple CSROs. We showcase our approach by addressing a long-standing question encountered in body-centred-cubic Fe-Al alloys that see anomalous property changes upon heat treatment. We use it to evidence non-statistical B2-CSRO instead of the generally-expected D03-CSRO. We introduce quantitative correlations among annealing temperature, CSRO, and nano-hardness and electrical resistivity. Our approach is further validated on modified D03-CSRO detected in Fe-Ga. The proposed strategy can be generally employed to investigate short/medium/long-range ordering phenomena in different materials and help design future high-performance materials. Quantifying chemical short-range order (CSRO) remains a formidable for volume-averaged or 2D microscopy methods. Here the authors introduce a machine-learning approach that breaks the resolution limitations of atom probe tomography to reveal the 3D atomistic architecture of CSRO in Fe-based alloys.
摘要：
采用砂磨工艺获得了亚微米氧化铝复合粉体，用于制备微晶氧化铝陶瓷基板，研究了浆料组成对浆料流变学性质、生坯密度、生坯应力-应变行为的影响，以及烧结制度对平均晶粒尺寸和基板抗弯强度的影响。结果表明，固相含量、R值(增塑剂和黏结剂的质量比)和分散剂用量等关键因素决定了流延浆料的流变学性质。R值增大导致生坯强度和密度降低，提高固相含量有利于增加最大可流延厚度，优化工艺条件下可制备0.16~1.20 mm的坯片。当烧结温度为1 550 ℃、升温速率为2.5 ℃/min、保温时间为60 min时，制备的陶瓷基板平均晶粒尺寸为1.1 μm左右，晶粒尺寸分布均匀，抗弯强度达到(440±25) MPa。 The submicron Al2O3 composite powder was obtained by sand milling process, which was used to prepare fine grained Al2O3 ceramic substrates. The effect of slurry composition on rheological properties of slurry, bulk density and stress-strain behavior of green tape was investigated, and the influence of sintering schedule on average grain size and flexural strength of ceramic substrate was also studied. The results show that key factors such as solid content, R value (mass ratio of plasticizer to binder) and dispersant dosage determine the rheological properties of slurry. The increase of R value leads to the reduction of tensile strength and density of green tape, and the increase of solid content is beneficial to increase the possible maximum casting thickness. Under the optimized process conditions, 0.16~1.20 mm green sheets can be prepared. At a sintering temperature of 1 550 ℃, a heating rate of 2.5 ℃/min and a holding time of 60 min, the average grain size of the prepared ceramic substrate is about 1.1 μm, the grain size distribution is uniform, and the flexural strength reaches (440±25) MPa.
摘要：
Producing ultrafine-grained (UFG) microstructures with enhanced thermal stability is an important yet challenging route to further improve mechanical properties of structural materials. Here, a highperformance bulk UFG copper that can stabilize even at temperatures up to 750 degrees C ( - 0.75 T m , T m is the melting point) was fabricated by manipulating its recrystallization behavior via low alloying of Co. Addition of 1 wt.%-1.5 wt.% of Co can trigger quick and copious intragranular clustering of Co atoms, which offers high Zener pinning pressure and pins the grain boundaries (GBs) of freshly recrystallized ultrafine grains. Due to the fact that the subsequent growth of the coherent Co-enriched nanoclusters was slow, sufficient particles adjacent to GBs remained to inhibit the migration of GBs, giving rise to the UFG microstructure with prominently high thermal stability. This work manifests that the strategy for producing UFGs with coherent precipitates can be applied in many alloy systems such as Fe- and Cu-based, which paves the pathway for designing advanced strain-hardenable UFGs with plain compositions. (c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.
期刊：
CHEMISTRY-AN ASIAN JOURNAL,2023年18(3):e202201152- ISSN：1861-4728
通讯作者：
Jia, Chuankun(jiachuankun@csust.edu.cn)
作者机构：
[Dr. Minyuan Guan; Kaiyun Zhou; Dr. Minyuan Guan Dr. Minyuan Guan Dr. Minyuan Guan; Kaiyun Zhou Kaiyun Zhou Kaiyun Zhou] Huzhou Power Supply Company of State Grid Zhejiang Electric Power Company Ltd., Huzhou, 313000 P. R. China;Huzhou Electric Power Design Institute Company Ltd., Huzhou, 313000 P. R. China;Institute of Energy Storage Technology, Changsha University of Science & Technology, Changsha, 410114 P. R. China;College of Materials Science and Engineering, Changsha University of Science & Technology, Changsha, 410114 P. R. China;[Murong He; Hu Fu; Xinan Wang; Dr. Fangfang Zhong; Prof. Mei Ding; Prof. Chuankun Jia; Murong He Murong He Murong He; Hu Fu Hu Fu Hu Fu; Xinan Wang Xinan Wang Xinan Wang; Dr. Fangfang Zhong Dr. Fangfang Zhong Dr. Fangfang Zhong; Prof. Mei Ding Prof. Mei Ding Prof. Mei Ding; Prof. Chuankun Jia Prof. Chuankun Jia Prof. Chuankun Jia] Institute of Energy Storage Technology, Changsha University of Science & Technology, Changsha, 410114 P. R. China<&wdkj&>College of Materials Science and Engineering, Changsha University of Science & Technology, Changsha, 410114 P. R. China
通讯机构：
[Prof. Chuankun Jia; Prof. Chuankun Jia Prof. Chuankun Jia Prof. Chuankun Jia] I;Institute of Energy Storage Technology, Changsha University of Science & Technology, Changsha, 410114 P. R. China<&wdkj&>College of Materials Science and Engineering, Changsha University of Science & Technology, Changsha, 410114 P. R. China
关键词：
energy storage;graphene;membrane;redox flow battery;two-dimensional materials
通讯机构：
[Si’an Chen] S;Science and Technology on Advanced Ceramic Fibers & Composites Laboratory, College of Aerospace Science and Engineering, National University of Defense Technology, Changsha, People’s Republic of China
摘要：
Polymer-derived SiBCN ceramics are well known for their outstanding thermal stability. Although they possess outstanding thermal stability, SiBCN ceramics are easily to decompose out Si3N4 and SiC crystalline phases at high temperature leading to thermal stability worsen. Here, to reduce the Si3N4 crystallization precipitation in SiBCN ceramics, the N contents are reduced from 25 to 8.09 wt%, 11.44 and 14.51 wt%, by adding polycarbosilane into polyborosilazane, respectively. The experimental results illustrated that the precipitation temperature of Si3N4 phase in modified S1-S3 ceramics increased to 1800 degrees C which was higher than that of S0 ceramics (1600 degrees C). The results indicated that the crystalline precipitation of Si3N4 in SiBCN ceramics can be suppressed at a high-temperature environment via declining N content, which may provide a new strategy for decreasing carbothermal reduction. In addition, the original SiBCN ceramic had a weight change of 31.7% at T > 1800 degrees C, while the weight change of modified SiBCN ceramics significantly reduced to 15.7 similar to 19.5%, which attributed to the decrease in carbothermal reduction.
