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Science China materials 2023年第5期66卷 2061-2070页

作者：柳洁杨青青邹冀王为民王新刚傅正义 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Hubei Longzhong Laboratory Xiangyang 441000China Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai 201899China

以硼热/碳热还原合成高熵二硼化物粉体为原料,在2000℃/单轴加压50 MPa条件下,经10分钟放电等离子烧结,成功制备了含有~2 vol%的氧化物和~1 vol%气孔的高熵(Ti_(0.2)Zr_(0.2)Nb_(0.2)Hf_(0.2)Ta_(0.2))B_(2)陶瓷(HEBs).经研究确认,其中... 详细信息

以硼热/碳热还原合成高熵二硼化物粉体为原料,在2000℃/单轴加压50 MPa条件下,经10分钟放电等离子烧结,成功制备了含有~2 vol%的氧化物和~1 vol%气孔的高熵(Ti_(0.2)Zr_(0.2)Nb_(0.2)Hf_(0.2)Ta_(0.2))B_(2)陶瓷(HEBs).经研究确认,其中残留氧化物是固溶少量硼和碳的m-(Hf,Zr)O_(2).室温下HEBs的弹性模量、维氏硬度和断裂韧性分别为508.5 GPa、17.7±0.4 GPa和4.2±0.2 MPa m^(1/2).烧结得到的HEBs具有优良的抗弯强度,特别是其高温强度.HEBs在室温、1600和1800℃下的四点抗折强度分别为400.4±47.0 MPa、695.9±55.9 MPa和751.6±23.2 MPa.对1800℃下断裂的HEBs样品进行了失效分析,在其拉伸和断裂面附近区域,仅在裂纹尖端和孔隙边缘发现了数量有限的位错线的存在,没有观察到位错运动的痕迹.本研究首次报道了高熵二硼化物陶瓷的高温强度,发现其强度直至1800℃并无衰减,并对其高温下的强韧化机制进行了有益的探讨.

关键词： borides high-entropy ceramics high-temperature strength mechanical properties microstructure

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Pd-La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)composite as active and stable oxygen electrode for reversible solid oxide cells

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Journal of Rare Earths 2023年第4期41卷 599-604页

作者： Rui Yang Yunfeng Tian Yun Liu Jian Pu Bo Chi Center for Fuel Cell Innovation State Key Laboratory of Material Processing and Die&Mould TechnologyHuazhong University of Science and TechnologyWuhan 430074China Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization School of Materials Science and PhysicsChina University of Mining and TechnologyXuzhou 221116China

To promote the electrocatalytic activity and stability of traditional(a_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(LSCF)oxygen electrodes in reversible solid oxide cells(RSOCs),conventional physical mixed method was used to prepare the Pd-LSCF composite oxygen *** cell with Pd-LSCF|GDC|YSZ|Ni-YSZ configuration shows perfect electrochemical performance in both solid oxide fuel cell(SOFC)mode and solid oxide electrolysis cell(SOEC)*** the SOFC mode,the cell achieves a power density of 1.73 W/cm^(2)at800℃higher than that of the LSCF oxygen electrode with 1.38 W/cm^(2).In the SOEC mode,the current density at 1.5 V is 1.67 A/cm^(2)at 800℃under 50 vol%steam ***,the reversibility and stability of the RSOCs were tested during 192 h long-term reversible *** degradation rate of the cell is only 2.2%/100 h and 2.5%/100 h in the SOEC and the SOFC modes,*** results confirm that compositing Pd with the LSCF oxygen electrode can considerably boost the electrochemical performance of LSCF electrode in RSOCs field.

关键词： Reversible solid oxide cells Composite Oxygen electrode La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ) Electrochemical performance Rare earths

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Air sensitivity of electrode materials in Li/Na ion batteries:Issues and strategies

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InfoMat 2022年第6期4卷 83-108页

作者： Ruiwang Zhang Sijie Yang Haobo Li Tianyou Zhai Huiqiao Li State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhanChina

With the development of electrode materials in lithium ion batteries-upgrading from LiCoO_(2)and LiFePO_(4)to Ni-rich layered oxides,and the shifting of battery systems from high cost lithium ion to low cost sodium ion technology,the air sensitivity of the electrode materials has become an increasingly important issue in both production and ***,the air sensitivity of electrode materials must be carefully considered throughout nearly all stages of their life,including material design,synthesis,production,storage,packaging,transportation,and battery ***,a fundamental understanding of the air degradation mechanism of electrode materials and the exploration of new methods to enhance their air stability are of great significance for the development of batteries with better ***,we provide a review of the issues related to air exposure of electrode materials in Li/Na ion batteries,including factors related to air sensitivity,degradation mechanisms,and recent progress in improving their air *** merits and existing challenges of different strategies are presented,and a rational design perspective as well as general principles for evaluating air stability are proposed.

关键词： air sensitivity air stability electrode materials lithium ion batteries sodium ion batteries

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Self-Cooling Hollow Mold With Containing Water and Its Effect on Microstructure and Mechanical Properties 75

Self-Cooling Hollow Mold With Containing Water and Its Effec...

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75th World Foundry Congress, WFC 2024

作者： Xu, Jingying Kang, Jinwu Mao, Weimin School of Materials Science and Engineering University of Science and Technology Beijing Beijing100083 China School of Materials Science and Engineering Key Laboratory for Advanced Materials Processing Technology Tsinghua University Beijing100084 China

The solidification process of castings directly determines the intrinsic quality and performance of castings, so controlling the cooling process during solidification of castings can eliminate or reduce defects such as shrinkage and porosity, cracks, deformation, etc., and then improve the performance of castings. 3D printing sand mold technology provides more options for the production of complex and high-quality castings, and improves the flexibility and innovation of the design of the sand structure. In order to control the sequential solidification of the castings, a new process of self-cooling hollow mold with containing water is proposed. The hollow mold is of a multi-shell structure which can contain water in the gaps between shells. Thus, it is convenient than the water dipping method or the bottom water cooling chill plate method. After pouring the molten metal, cooling water is pumped into the gaps between the shell layers, and the water level of the cooling water can be controlled to rise gradually to drive the solidification front per request, so as to realize the forced cooling of the castings from bottom to top, i.e., sequential solidification. By the casting experiment of barrels of aluminum alloy A357, it was found that the water cooling of the multi-layer shell hollow sand mold accelerates the cooling rate of the castings, the cooling rate increased by approximately 190% compared to natural cooling. The tensile strength of castings is 160 MPa, representing an increase of 14.3%, and the microhardness is 72.3 HV, showing an increase of about 43.5%. © 2024 75th World Foundry Congress, WFC 2024. All rights reserved.

关键词： Aluminum castings

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Special issue on electrochemical conversion and utilization of hydrogen energy

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Frontiers in Energy 2024年第3期18卷 263-264页

作者： Yun ZHENG Bo YU Xiaogang FU Jiujun ZHANG Institute of New Energy Materials and Engineering School of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China State Key Laboratory of Solidification Processing Atomic Control&Catalysis Engineering LaboratorySchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China

The concerns over energy crisis and climate change caused by the excessive consumption of fossil fuels and the associated emission of greenhouse gases, have driven many countries to develop policies for an energy transition into zero-carbon energy sources, essentially aiming at decarbonizing their energy systems. Among various renewable sources, hydrogen has been hailed as an ideal alternative to provide secure, cost-effective, and non-polluting energy. In recent years, there has been noteworthy progress in hydrogen electrochemical conversion and utilization techniques and devices, including water electrolyzers, proton-exchange membrane fuel cells (PEMFCs), solid oxide fuel cells (SOFCs), etc. Each of these technologies has yielded a series of encouraging advances. To showcase these recent advances, Frontiers in Energy is launching a special issue titled “electrochemical conversion and utilization of hydrogen energy”.

关键词： hydrogen energy. electrochemical

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Ultrasensitive Frequency Shifting of Dielectric Mie Resonance near Metallic Substrate

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Research 2022年第4期2022卷 155-163页

作者： Chuanbao Liu Changxin Wang Junhong Chen Yanjing Su Lijie Qiao Ji Zhou Yang Bai School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China State Key Laboratory of New Ceramics and Fine Processing Tsinghua UniversityBeijing 100084China

Dielectric resonators on metallic surface can enhance far-field scattering and boost near-field response having promising applications in nonlinear optics and reflection-type ***,the dependence of gap size between dielectric resonator and metallic surface on Mie resonant frequency is complex and desires a comprehensive physical ***,we systematically study the effect of metallic substrate on the magnetic dipole(MD)resonant frequency at X-band by placing a high permittivity CaTiO_(3) ceramic block on metallic substrate and regulating their gap *** simulated and experimental results show that there are two physical mechanisms to codetermine the metallic substrate-induced MD *** greatly enhanced electric field pair in the gap and the coupling of MD resonance with its mirror image are decisive for small and large gaps,respectively,making the MD resonant frequency present an exponential blue shift first and then a slight red shift with increasing gap ***,we use the two mechanisms to explain different frequency shifting properties of ceramic sphere near metallic ***,taking advantage of the sharp frequency shifting to small gaps,the ceramic block is demonstrated to accurately estimate the thickness or permittivity of thin film on metallic substrate through a governing equation derived from the method of symbolic *** believe that our study will help to understand the resonant frequency shifting for dielectric particle near metallic substrate and give some prototypes of ultrasensitive detectors.

关键词： metallic ceramic shifting

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An atomic insight into effect of grain boundary on diffusion behavior of Cu/Al dissimilar materials undergoing ultrasonic welding

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Journal of Iron and Steel Research International 2024年第10期31卷 2555-2567页

作者： Jing-wei Yang Chu-hao Xie Jie Zhang Zong-ye Ding Jian Qiao School of Mechatronic Engineering and Automation Foshan UniversityFoshan528225GuangdongChina School of Mechanical Engineering University of Science and Technology BeijingBeijing100083China Shanghai Key Laboratory of Materials Laser Processing and Modification School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai200240China State Key Laboratory of Advanced Brazing Filler Metals&Technology Zhengzhou Research Institute of Mechanical Engineering Co.Ltd.Zhengzhou450001HenanChina

The diffusion processes in bicrystalline Cu/Al joints,characterized by typical high-angle grain boundaries(GBs),were investigated using molecular dynamics *** was found that GBs facilitated the diffusion of both Cu and Al atoms,predominantly enhancing the migration of Cu atoms into Al *** to mean squared displacement results,the movement of Al atoms within Al matrix was more vigorous than that of Cu *** mechanisms of atomic rearrangement,dislocation movement,stacking fault formation,and dynamic recrystallization were *** the compression and initial welding stages,the mismatch in lattice constants and the twisting of grains initiated a squeeze-induced rearrangement of Al atoms at the interface,leading to the formation of dislocations and *** the advanced stages of welding,the plastic deformation primarily occurred within Al matrix,marked by the emergence of dislocations,stacking faults,and GB ***,the shearing effect during the ultrasonic welding process,combined with GB sliding,collectively induced grain recrystallization at the ***,the diffusion between Cu/Al joints could be enhanced by increasing the vibration frequency,due to a significant rise in the number of amorphous regions.

关键词： Grain boundary Molecular dynamics Diffusion behavior Ultrasonic welding Dissimilar material

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Advances in ultra-high temperature ceramics,composites,and coatings

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Journal of advanced Ceramics 2022年第1期11卷 1-56页

作者： Dewei NI Yuan CHENG Jiaping ZHANG Ji-Xuan LIU Ji ZOU Bowen CHEN Haoyang WU Hejun LI Shaoming DONG Jiecai HAN Xinghong ZHANG Qiangang FU Guo-Jun ZHANG State Key Laboratory of High Performance Ceramics&Superfine Microstructure Structural Ceramics and Composites Engineering Research CenterShanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Center for Composite Materials and StructuresHarbin Institute of TechnologyHarbin 150001China Shaanxi Key Laboratory of Fiber Reinforced Light Composite Materials Northwestern Polytechnical UniversityXi’an 710072China State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional MaterialsDonghua UniversityShanghai 201620China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China University of Chinese Academy of Sciences Beijing 100049China

Ultra-high temperature ceramics(UHTCs)are generally referred to the carbides,nitrides,and borides of the transition metals,with the Group IVB compounds(Zr&Hf)and TaC as the main *** UHTCs are endowed with ultra-high melting points,excellent mechanical properties,and ablation resistance at elevated *** unique combinations of properties make them promising materials for extremely environmental structural applications in rocket and hypersonic vehicles,particularly nozzles,leading edges,and engine components,*** addition to bulk UHTCs,UHTC coatings and fiber reinforced UHTC composites are extensively developed and applied to avoid the intrinsic brittleness and poor thermal shock resistance of bulk ***,high-entropy UHTCs are developed rapidly and attract a lot of attention as an emerging direction for ultra-high temperature *** review presents the state of the art of processing approaches,microstructure design and properties of UHTCs from bulk materials to composites and coatings,as well as the future directions.

关键词： ultra-high temperature ceramics(UHTCs) coatings composites high-entropy ultra-high temperature ceramics

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One-step solvothermal preparation of Fe-doped Ni_(0.85)Se/NF:An efficient catalyst for the oxygen evolution reaction

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ChemPhysMater 2025年第1期4卷 78-85页

作者： Longqi Zhu Runze Wang Chen Wang Shuhan Yang Haizhen Liu Bo Xing Honghui Cheng Kuikui Wang Institute of Materials for Energy and Environment Laboratory of New Fiber Materials and Modern TextileGrowing Basis for State Key LaboratoryCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured MaterialsGuangxi UniversityNanning 530004China National Engineering Laboratory of Circular Economy Sichuan University of Science and EngineeringZigong 643000China School of Mechanical Engineering Yangzhou UniversityYangzhou 225127China Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology Changzhou UniversityChangzhou 213164China

Metal-cation doping is a fundamental strategy for enhancing catalyst ***-doped Ni_(0.85)Se/NF(Fe-Ni_(0.85)Se/NF)nanoparticles were prepared at 80°C via Fe^(2+)etching *** addition of Fe altered the coordination environment of the Ni species along with the catalyst's morphology,creating additional active ***,the synergistic interaction between the bimetallic components augmented the built-in activity and accelerated reaction *** Fe-Ni_(0.85)Se/NF electrocatalysts demonstrated remarkable catalytic activity for the oxygen evolution reaction(OER),with an acceptable overpotential of 276 mV and a Tafel slope of 58.1 mV dec^(−1)at 100 mA cm^(−2).Moreover,they demonstrated exceptional *** situ Raman and X-ray photoelectron spectroscopy(XPS)analyses showed that the excellent OER performance stemmed from the reconstruction-induced hydroxyl *** study offers a novel approach for streamlining the synthesis procedures and reducing the experimental costs for developing high-efficiency electrocatalysts.

关键词： Doping Selenylation Hydrothermal reaction Oxygen evolution reaction Electrocatalysts

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Enhanced reversible hydrogen storage properties of wrinkled graphene microflowers confined LiBH_(4) system with high volumetric hydrogen storage capacity

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materials Reports(Energy) 2024年第1期4卷 79-88页

作者： Zhenglong Li Kaicheng Xian Hao Chen Mingxia Gao Shanqing Qu Meihong Wu Yaxiong Yang Wenping Sun Chao Gao Yongfeng Liu Xin Zhang Hongge Pan Institute of Science and Technology for New Energy Xi'an Technological UniversityXi'an710021PR China State Key Laboratory of Silicon and Advanced Semiconductor Materials Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang ProvinceSchool of Materials Science and EngineeringZhejiang UniversityHangzhou310027PR China Department of Polymer Science and Engineering MOE Key Laboratory of Macromolecular Synthesis and FunctionalizationZhejiang UniversityHangzhou310027PR China

LiBH_(4)with high hydrogen storage density,is regarded as one of the most promising hydrogen storage ***,it suffers from high dehydrogenation temperature and poor reversibility for practical *** is effective in achieving low dehydrogenation temperature and favorable ***,graphene can serve as supporting materials for LiBH_(4)catalysts and also destabilize LiBH_(4)via interfacial ***,graphene has never been used alone as a frame material for nanoconfining LiBH_(4).In this study,graphene microflowers with large pore volumes were prepared and used as nanoconfinement framework material for LiBH_(4),and the nanoconfinement effect of graphene was *** loading 70 wt%of LiBH_(4) and mechanically compressed at 350 MPa,8.0 wt% of H2 can be released within 100 min at 320C,corresponding to the highest volumetric hydrogen storage density of 94.9 g H2 L^(-1)ever *** to the nanoconfinement of graphene,the rate-limiting step of dehydrogenation of nanoconfined LiBH_(4) was changed and its apparent activation energy of the dehydrogenation(107.3 kJ mol^(-1))was 42%lower than that of pure LiBH_(4).Moreover,the formation of the intermediate Li_(2)B_(12)H_(12) was effectively inhibited,and the stable nanoconfined structure enhanced the reversibility of LiBH_(4).This work widens the understanding of graphene's nanoconfinement effect and provides new insights for developing high-density hydrogen storage materials.

关键词： Hydrogen storage LiBH_(4) Nanoconfinement Graphene High capacity

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