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A novel cobalt-free oxide dispersion strengthened medium-entropy alloy with outstanding mechanical properties and irradiation resistance

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Journal of Materials Science & technology 2023年第21期152卷 190-200页

作者： Ao Fu Bin Liu Bo Liu Yuankui Cao Jian Wang Tao Liao Jia Li Qihong Fang Peter K.Liaw Yong Liu State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Key Laboratory of Radiation Physics and Technology of Ministry of Education Institute of Nuclear Science and TechnologySichuan UniversityChengdu 610064China State Key Lab of Advanced Design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996USA

A novel cobalt-free oxide dispersion strengthened(ODS)equiatomic FeCrNi medium entropy alloy(MEA)was successfully fabricated through mechanical alloying and hot extrusion(HE).The ODS FeCrNi MEA is composed of a single face-centered cubic(FCC)matrix,in which highly dispersed oxide nanoparticles,including Y_(2)Ti_(2)O_(7),Y_(2)TiO_(5) and Y_(2)O_(3),are uniformly *** with the FeCrNi MEA,the ODS FeCrNi MEA exhibits the improved yield strength(1120 MPa)and ultimate tensile strength(1274 MPa)with adequate ductility retention(12.1%).Theoretical analysis of the strengthening mechanism indicates that the high strength is mainly attributed to the grain-boundary strengthening caused by fine grains and the precipitation strengthening resulted from the oxide ***,the matrix that easily activates mechanical twinning during the deformation process is the main reason to ensure moderate *** addition,the introduction of high-density oxide nanoparticles can disperse the defect distri-bution and suppress the defect growth and irradiation-induced segregation,leading to the excellent irra-diation *** findings provide innovative guidance for the development of high-performance structural materials for future nuclear energy applications with balanced strength and ductility.

关键词： Medium-entropy alloys Irradiation Oxide nanoparticles Strength Deformation mechanism

Manganese-based oxides cathodes for potassium-ion batteries: a review

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Journal of Energy Chemistry 2025年 108卷 1-18页

作者： Yue, Qinggang Xia, Maoting Zhou, Jiang Cheng, Juanjuan Lu, Bingan School of Physics and Electronics Hunan University Hunan Changsha410082 China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Hunan Changsha410082 China School of Materials Science and Engineering and Key Laboratory of Nonferrous Metal Materials Science and Engineering Ministry of Education Central South University Hunan Changsha410083 China School of Materials Science and Engineering Hunan Provincial Key Lab of Advanced Materials for New Energy Storage and Conversion Hunan University of Science and Technology Hunan Xiangtan411201 China

Potassium-ion batteries (PIBs) were recognized for their natural abundance, high theoretical output voltage, and the availab.lity of commercialized graphite anodes. However, the development of high-performance manganese-based layered oxide cathodes—a leading candidate for PIB systems—has been fundamentally constrained by irreversible phase transitions (PT) during the cycling process, manifesting as severe structural degradation and capacity fading. This review presents a transformative paradigm integrating machine learning (ML) with multiscale characterization to analyse the complex phase transition mechanisms in Mn-based cathodes. Through systematic ML-driven interrogation of structure–property relationships, we establish quantitative descriptors for phase stability and develop predictive models for transition dynamics. Furthermore, we highlight recent breakthroughs in cross-disciplinary approaches, enabling the rational design of PT-mitigated cathode architectures. By consolidating these insights into a unified knowledge framework, this work provides strategic guidelines for developing structurally robust Mn-based cathodes and outlines future research directions for next-generation PIB systems. © 2025 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences.

关键词： Setting

Research on Cracking Mechanism of Aero-Engine Thermocouple Bearing Ring Under High-Temperature Creep Test

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SSRN 2024年

作者： Wang, Songjun He, Jianjun Gong, Zhihui Cai, Yuhui Yao, Biqing Xiao, Tingyi School of Energy and Power Engineering Changsha University of Science and Technology Changsha410114 China State Key Laboratory of Advanced Design and Manufacture for Vehicle Body Hunan University Changsha40082 China

AbstractsThe thermocouple bearing ring in aero-engine have prematurely cracked during service, posing a significant safety hazard. This paper analyzes the microstructure and fracture behavior of K4169 high-temperature superalloy specimens under thermomechanical loading considering this phenomenon. The results revealed that a small amount of needle-like δ-phases and an increased number of Laves phases accumulated around the grain boundaries after direct aging treatment. After solution treatment followed by aging, more twinning features were observed at the grain boundaries, and the Laves phase was diffusely distributed. No needle-like δ-phases were found at 710°C, indicating that the heat treatment was optimal. At 650°C, the alloy demonstrated excellent creep resistance, characterized by distinct stages of constant velocity and accelerated creep. On the specimen's surface, twins and a few dislocations appeared, while the Laves phase precipitated and partially aggregated at the grain boundaries, accompanied by the formation of small voids. As the temperature increases, the Laves phase content increases along with the formation of voids. These Laves phases were accompanied by needle-like δ phases, forming 'bands' that facilitated crack initiation, primarily along the grain boundaries. At 650°C, secondary cracks appeared at the fracture, indicative of predominantly ductile fracture behavior. With an increase in temperature to 710°C, precipitation of the second phase increased significantly, leading to pronounced stress concentration. Consequently, the fracture mode transitioned from ductile fracture to a ductile-brittle mixed fracture. © 2024, The Authors. All rights reserved.

关键词： Grain boundaries

A Chip-Wound Inductors Defect Detection Method Based on Object Detection and Semantic Segmentation

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SSRN 2024年

作者： Wang, Zhuanwang Yang, Wenfeng Hu, Zhaochuan Zhang, Hang Liu, Jian Li, Rong Chen, Bing Li, Mingze State Key Laboratory of Advanced Design and Manufacture for Vehicle Body Hunan University Changsha410082 China College of Automotive and Mechanical Engineering Changsha University of Science and Technology Changsha410114 China

The accurate and efficient detection of chip-wound inductors is of paramount importance in the production of electronic components and the application and development of related products. Nevertheless, conventional detection techniques are inadequate to meet the demands of the diverse types, high precision, and high efficiency of detection required at this time. This study proposes a deep learning-based method for the detection of diverse types of defects in chip-wound inductors. The method addresses the issue of multiple types of appearance defects and high detection difficulty by combining object detection and semantic segmentation. Firstly, the large convolutional kernel mechanism is introduced to You Only Look Once version 8 (YOLOv8), the backbone structure is based on Large Selective Kernel Network (LSKNet), and the LK-selected sub-block is improved, which enables the accurate detection of solder void and crush defects in inductors. Subsequently, the U-Net (UNet) semantic segmentation model was employed, and the Convolutional Block Attention Module (CBAM) mechanism was introduced to enhance the feature extraction capability and achieve accurate segmentation of the inductor region. This was followed by pattern recognition of the position and size defects of the inductor based on the segmentation results. The experimental results show that the proposed diverse types of detection method demonstrated a defect recognition accuracy of up to 99.60% and an efficiency of 0.23s/each, effectively and efficiently detecting the inductor's defects. Furthermore, the improved YOLOv8 network achieved 90.95% mean average precision (mAP), while the improved UNet network achieved 87.57% mean intersection over union (MioU), outperforming other networks. © 2024, The Authors. All rights reserved.

关键词： Semantic Segmentation

Research on Cracking Mechanism of Aero-Engine Thermocouple Bearing Ring Under High-Temperature Creep Test

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SSRN 2024年

The thermocouple bearing ring in aero-engine have prematurely cracked during service, posing a significant safety hazard. This paper analyzes the microstructure and fracture behavior of K4169 high-temperature superalloy specimens under thermomechanical loading considering this phenomenon. The results revealed that a small amount of needle-like δ-phases and an increased number of Laves phases accumulated around the grain boundaries after direct aging treatment. After solution treatment followed by aging, more twinning features were observed at the grain boundaries, and the Laves phase was diffusely distributed. No needle-like δ-phases were found at 710°C, indicating that the heat treatment was optimal. At 650°C, the alloy demonstrated excellent creep resistance, characterized by distinct stages of constant velocity and accelerated creep. On the specimen's surface, twins and a few dislocations appeared, while the Laves phase precipitated and partially aggregated at the grain boundaries, accompanied by the formation of small voids. As the temperature increases, the Laves phase content increases along with the formation of voids. These Laves phases were accompanied by needle-like δ phases, forming 'bands' that facilitated crack initiation, primarily along the grain boundaries. At 650°C, secondary cracks appeared at the fracture, indicative of predominantly ductile fracture behavior. With an increase in temperature to 710°C, precipitation of the second phase increased significantly, leading to pronounced stress concentration. Consequently, the fracture mode transitioned from ductile fracture to a ductile-brittle mixed fracture. © 2024, The Authors. All rights reserved.

关键词： Grain boundaries

Foveated glasses-free 3D display with ultrawide field of view via a large-scale 2D-metagrating complex

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Light(Science & Applications) 2021年第11期10卷 2217-2225页

作者： Jianyu Hua Erkai Hua Fengbin Zhou Jiacheng Shi Chinhua Wang Huigao Duan Yueqiang Hu Wen Qiao Linsen Chen School of Optoelectronic Science and Engineering&Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University215006SuzhouChina Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province&Key Lab of Modern Optical Technologies of Education Ministry of China Soochow University215006SuzhouChina State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan University410082ChangshaChina SVG Optronics Co.Ltd215026SuzhouChina

Glasses-free three-dimensional(3D)displays are one of the game-changing technologies that will redefine the display industry in portable electronic ***,because of the limited resolution in state-of-the-art display panels,current 3D displays suffer from a critical trade-off among the spatial resolution,angular resolution,and viewing *** by the so-called spatially variant resolution imaging found in vertebrate eyes,we propose 3D display with spatially variant information *** experiences with smooth motion parallax are maintained at the central view,while the viewing angle is enlarged at the periphery *** is enabled by a large-scale 2D-metagrating complex to manipulate dot/linear/rectangular hybrid shaped ***,a video rate full-color 3D display with an unprecedented 160°horizontal viewing angle is *** thin and light form factors,the proposed 3D system can be integrated with off-the-shelf purchased flat panels,making it promising for applications in portable electronics.

关键词： portable spatially glasses

Probing the Effect of Static Thermal Aging and Ultraviolet Aging on Performance Characteristic of Lithium Complex Grease and Polyurea Grease

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SSRN 2023年

作者： Ren, Guanlin Zhou, Changjiang Fan, Xiaoqiang Liu, Yahui State Key Laboratory of Advanced Design and Manufacture for Vehicle Body Hunan University Changsha410082 China Southwest Jiaotong University Chengdu610031 China Beijing Engineering Research Center of Precision Measurement Technology and Instruments Beijing University of Technology Beijing100124 China

Space equipment inevitablely suffers from ultraviolet (UV) irradiation and thermal aging, which results in the structure/composition change and properties decrease. In this study, the lithium complex grease (LCG) and polyurea grease (PUG) were prepared with three different concentrations (20%, 15%, 10%), and the effect of static thermal (ST) aging and UV aging on physicochemical, rheological and tribological properties was investigated in detail. Results shows that the PUG (20%) exhibited the greatest physicochemical properties as a result of the high tenacity spiral polyurea fiber's strong interaction with PAO40. UV and ST aging resulted in the oxidation of base oil and physical/chemical degradation of thickener, thereby decreased the dropping point and oil separation, as well as the changes of thixotropy. And ST aging led to higher oil-bleeding rate than UV aging, due to a higher degree of degradation for ST aging. The fresh LCG containing 10% thickener demonstrated the greatest tribological properties due to the synergistic action of tribo-chemical film and oil film. The tribological proeprties of LCG after ST aging was improved because the ST aging improved the flowbility. © 2023, The Authors. All rights reserved.

关键词： Thermal aging

A Human Active Lower Limb Model for Chinese Pedestrian Safety Evaluation

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Journal of Bionic Engineering 2021年第4期18卷 872-886页

作者： Fuhao Mo Dian Luo Zheng Tan Bo Shang Xiaojiang Lv Donghua Zhou State Key Laboratory of Advanced Design and Manufacture for Vehicle Body Hunan UniversityHunan 410082China School of Mechanical Engineerings Hunan University of Science and Technology Xiangtan 411201China Pan Asia Technical Automotive Center Co. LtdShanghai 201201China Zhejiang Key Laboratory of Automobile Safety Technology Geely Automobile Research InstituteNingbo 315336China Shanghai Key Laboratory of Forensic Medicine Shanghai Forensic Service PlatformAcademy of Forensic ScienceMinistry of JusticeShanghai 200063China

A subsystem impactor test for pedestrian lower limb injury evaluation has been brought in China New Car Assessment Protocol(CNCAP).Concerning large anthropometric differences of the people from different countries,the present study aims to establish and validate a finite element lower limb model representing 50th Chinese male size for pedestrian safety research,then compare its biomechanical responses with the general models currently in wide use in the world for pedestrian safety *** the vehicle-pedestrian impact loading environment,the previously developed lower limb model with three-dimensional muscles was adjusted and validated through the related ***,the biomechanical responses of the validated model were compared with the Total Human Model for Safety(THUMS)and advanced Pedestrian Legform Impactor(aPLI)models by combing with four typical *** results showed that both consistency and significant differences of biomechanical responses existed between the present model and the other two *** injury measurements of the thigh region of the present model showed extremely large differences with the other two models,while the tibia and Medial Collateral Ligament(MCL)injury measurements show similar ***,it can be concluded that directly using the aPLI or THUMS models for Chinese pedestrian safety evaluation is not robust concerning both kinematic responses and injury measurements.

关键词： lower limb injury biomechanics human body modeling pedestrian safety finite element analysis

3D/4D additive-subtractive manufacturing of heterogeneous ceramics

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Journal of Materials Science & technology 2024年第34期201卷 210-221页

作者： Guo Liu Xinya Lu Xiaofeng Zhang Yan Zhao Shenghui Yi Jingjun Xu Yuqi Zhan Jianan Yin Chengcheng Feng Zhifeng Zhou Peiyu Wang Zhou Chen Yunhu He Siyao Chen Pengchao Liu Jun Zuo Yu Dai Jian Wu Sida Liu Jian Lu Centre for Advanced Structural Materials City University of Hong Kong Shenzhen Research InstituteGreater Bay Joint DivisionShenyang National Laboratory for Materials ScienceShenzhen 518057China CityU-Shenzhen Futian Research Institute Shenzhen 518045China Hong Kong Branch of National Precious Metals Material Engineering Research Center City University of Hong KongHong Kong 999077China Department of Mechanical Engineering City University of Hong KongHong Kong 999077China Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China National Engineering Laboratory for Modern Materials Surface Engineering Technology&The Key Lab of Guangdong for Modern Surface Engineering Technology Institute of New MaterialsGuangdong Academy of ScienceGuangzhou 510650China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China Faculty of Materials Science Shenzhen MSU-BIT UniversityShenzhen 518100China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Physics and Materials Nanchang UniversityNanchang 330031China

The manufacturing of heterogeneous high-temperature material components is challenging for use in practical ***-dimensional(3D)printing provides solutions to programmable constructing ceramic ***,the development of heterogeneous ceramics is limited by low flexibil-ity of heterogeneity,geometrical complexity,structural resolution,manufacturing efficiency,and mate-rial *** this study,we demonstrated flexible and rapid approaches for fabricating complicated and precise heterogeneous ceramics by shape-changing(4D)or shape-keeping(3D)additive-subtractive manufacturing(ASM)*** shape-changing strategy for heterogeneous ceramics was achieved by global ceramization of heterogeneous precursors,while the shape-keeping strategy for heterogeneous ceramics was achieved by local receramization of homogeneous *** element analysis(FEA)simulations of the influence of the thermal shrinkage dominant in the shape-changing strategy on the shape deformation of heterogeneous ceramics could be valuable predictions of the experimental *** 3D/4D ASM methods are generic for high-temperature materials and extendable to metallic and dia-mond materials.

关键词： 3D/4D printing Additive-subtractive manufacturing Heterogeneous ceramics Elastomer-derived ceramics Local receramization