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Sparse identification-assisted exploration of the atomic-scale deformation mechanism in multiphase CoCrFeNi high-entropy alloys

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science china(Technological sciences) 2024年第4期67卷 1124-1132页

作者： XIAO Lu guo xiaoxiang SUN YuTong wang Gang LONG WeiMin LIAW Peter K. REN JingLi school of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China Academy of Mathematics and Systems science Chinese Academy of SciencesBeijing 100190China Institute of materials Shanghai UniversityShanghai 200444China SKL of Advanced Brazing Metals&Technology Zhengzhou Research Institute of Mechanical EngineeringZhengzhou 450001China Department of materials science and engineering The University of TennesseeKnoxvilleTN 37996USA

This study investigated the atomic-scale deformation mechanism of multiphase CoCrFeNi high-entropy alloys(heAs)at liquid helium,liquid nitrogen,and room temperatures.A million-atom multiphase heA was prepared using molecular dynamics simulation involving melt and quench *** heA exhibited high-density dislocations and some twins,consistent with experimental *** analysis revealed an inconsistent evolution of the microstructure under tensile *** particular,the elastic and initial plastic stages exhibited an increase in the disordered structure at the expense of the face-centered cubic and hexagonal close-packed structures,followed by a subsequent transformation involving multiple structural ***,through sparse identification,a model depicting microstructural evolution during tension was extracted for the CoCrFeNi heA at three typical temperatures and three tensile *** model highlighted the importance of the body-centered cubic structure in the evolutionary process.

关键词： high-entropy alloy data-driven method microstructure evolution multiphase structure molecular dynamics simulation

Preparation of Superfine-Cemented Carbide by Spark Plasma Sintering

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Journal of Wuhan university of Technology(materials science) 2006年第1期21卷 42-45页

作者：解迎芳王兴庆 school of materials science and {3. Shanghai University Shanghai 200072 China

92WC-8Co puwder mixture with superfine-tungsten carbide was respectively sintered by spark plasma sintering（ SPS ） and sintering isostutic pressure （SIP）. Complete dense samples with 200 nm WC grains and 94.2HRA hardness were prepared by spark plasma sintering at 1 150 ℃ and under 4.5 kN for 5 minutes. SIP was carried out at 1 400 ℃ for 3. minutes with a result of 3.0-400 nm WC grains and 93.HRA hardness. The results show that sintering temperature is greatly decreased by SPS, sintering time is largely shortened and WC grain growth is effectively retarded. Micropores and drawb（wks in superfine-cemented carbide made by SPS are greatly declined, which is very useful to improving nwehanical properties.

关键词： spurk plasma sintering cemented carbide superfine grain sintering mechanism

Sintering of WC-Co powder with nanocrystalline WC by spark plasma sintering

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Rare Metals 2006年第3期25卷 246-252页

作者： wang xingqing XIE Yingfang guo hailiang O.Van der Biest J.Vleugels school of materials science and {3. Shanghai University Shanghai 200072 China materials engineering Faculty of engineering Katholikeke Universiteit Leuven Leuven 3000 Belgium

A 92WC-8Co powder mixture with 3. nm WC grains was prepared by strengthening ball milling and was then sintered by spark plasma sintering （SPS） at 1000-1200℃ for 5-18 rain under 10-25 kN, respectively. Movement of the position of low punch shown shrinkage of the sintered body began above 800℃. The shrinkage slowly rose as the temperature rose from 800 to 1000℃ and then quickly rose at above 1000℃ and then gradually rose at above 1150℃. The densities of the samples increased with an increase in sintering temperature, rapidly below 1100℃, and then gradually above 1100℃. WC grains grow gradually with increasing sintering temperature. The powder was sintered to near full density at 1100℃ for 5 rain under 10 kN. The best result of the sample with 275 nm WC grains and no pores was obtained at 1150℃ under 10 kN for 5 rain. The research found the graphite die had a function of carburization, which could compensate the sintered body for the lack of carbon, and had the normal microstructure.

关键词： nanocrystalline cemented carbide spark plasma sintering low temperature sintering strengthening ball milling

Effect of Phase Structure Evolution on Thermal Expansion and Toughness of (Nd1-xScx)2Zr2O7 (x = 0, 0.025, 0.05, 0.075, 0.1 ) Ceramics

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Journal of materials science & Technology 2017年第2期33卷 192-197页

作者： xiaoxiang Zhao Lei guo Caimei wang Yu Zhang Fuxing Ye school of materials science and {3. Tianjin University Tianjin 300072 China Tianjin Key Laboratory of Advanced Joining Technology Tianjin University Tianjin 300072 China Key Lab of Advanced Ceramics and Machining Technology of Ministry of Education Tianjin University Tianjin 300072 China

Nd2Zr2O7 is being explored as an alternate thermal barrier coating （TBC） material for operating above 13.0 ℃, and great effort has been made to enlarge its thermal expansion coefficient （TEC） and improve its toughness. In this study, Sc203.vvas doped to Nd2Zr2O7. The phase structure, TECs and toughness of （Nd1-xScx）2Zr2O7 （x = 0, 0.025, 0.05, 0.075, 0.1 ） compounds were investigated. （Nd1-xScx）2Zr2O7 （x = 0, 0.025, 0.05, 0,075） exhibited pyrochlore structure, while （Nd0.9Sc0.1）2Zr2O7 consisted of pyrochlore and fluorite phases. With the increase of the Sc203.content, the ordering degree of the pyrochlore in the compounds decreased. In （Nd1-xScx）2Zr2O7 series, （Nd0.925Sc0.075）2Zr2O7 exhibited the largest TEC, while the toughness of the compounds increased with increasing the Sc2O3.content. The related mechanisms were discussed based on the crystal structure analysis. Considering the TEC and toughness, 10 mol% Sc2O3.was sug- gested as the optimal doping content for Nd2Zr2O7 ceramic.

关键词： Thermal harrier coating Nd2Zr2O7 Doping Phase structure Thermal expansion coefficient Toughness

A comprehensive study on Li_(4)Si_(1-x)Ti_(x)O_(4) ceramics for advanced tritium breeders

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Journal of Advanced Ceramics 2020年第5期9卷 629-640页

作者： Yichao GONG Lin LIU Jianqi QI Mao YANG Junjie LI hailiang wang Hao guo guojun ZHANG Tiecheng LU school of materials science&{3. Xi’an University of TechnologyXi’an 710048China College of Physical science and Technology Sichuan UniversityChengdu 610064China Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China

hetero-element doped lithium orthosilicates have been considered as advanced tritium breeders due to the superior *** this work,Li_(4)Si_(1-x)Ti_(x)O_(4) ceramics were prepared by proprietary hydrothermal process and multistage reactive *** reaction mechanism of Li_(4)Si_(1-x)Ti_(x)O_(4) was put *** and SEM analyses indicate that insertion of Ti leads to lattice expansion,which promotes the grain growth and changes the fracture *** compressive tests show that the crush load increases almost four times by increasing x from 0 to ***,the thermal conductivity and ionic conductivity are the best when x=0.05 and x=0.1,*** cycling stability of Li_(4)Si_(1-x)Ti_(x)O_(4) pebbles was further appraised through investigating the changes of microstructure and crush *** undergoing thermal cycling,the Li_(4)Si_(1-x)Ti_(x)O_(4) still show higher crush load compared with Li_(4)SiO_(4),despite Ti segregation in some *** x=0.05 sample exhibits excellent thermal cycling *** summary,proper amount of Ti doping can improve the crush load,thermal and ionic conductivity,and thermal cycling stability of Li_(4)SiO_(4).

关键词： tritium ceramic breeders Li_(4)Si_(1-x)Ti_(x)O_(4) solid solutions crush load conductivity thermal cycling

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舰艇爆炸毁伤与防护若干关键问题研究进展

中国舰船研究 2024年第3期19卷 3-60页

作者：李营杜志鹏陈赶超王诗平侯海量李晓彬张攀张伦平孔祥韶李海涛郭君姚术健王志凯殷彩玉北京理工大学先进结构技术研究院北京100081 海军研究院北京100161 哈尔滨工程大学船舶工程学院黑龙江哈尔滨150001 海军工程大学舰船与海洋学院湖北武汉430033 武汉理工大学船海与能源动力工程学院湖北武汉430063 华中科技大学船舶与海洋工程学院湖北武汉430074 中国船舶科学研究中心江苏无锡214082 中南大学极端流动力能前沿科学中心湖南长沙410075

大型水面舰船和潜艇是支撑海军空间立体化作战的主要装备和移动平台,随着战斗部毁伤威力和制导精度的日益提高,加之毁伤载荷的多元化,其生存环境面临愈加严峻的挑战,因而开展舰艇爆炸毁伤与防护研究具有十分重要的意义。爆炸载荷下舰艇... 详细信息

大型水面舰船和潜艇是支撑海军空间立体化作战的主要装备和移动平台,随着战斗部毁伤威力和制导精度的日益提高,加之毁伤载荷的多元化,其生存环境面临愈加严峻的挑战,因而开展舰艇爆炸毁伤与防护研究具有十分重要的意义。爆炸载荷下舰艇结构的毁伤与防护是一个涉及爆炸力学、流体力学、结构动力学、材料学等多学科融合的交叉性问题,仍存在诸多难题有待研究。针对其中涉及的若干关键问题,围绕近年来国内外在舰艇爆炸载荷特性、毁伤响应机制及其防护技术与装备等方面的研究进展进行系统概述,指出当前研究存在的不足,并对舰艇爆炸毁伤与防护的发展趋势进行展望,旨在为未来舰艇高效毁伤与防护研究提供有价值的参考。

关键词：舰艇结构爆炸载荷毁伤机理防护技术

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Correlation between jerky flow and jerky dynamics in a nanoscratch on a metallic glass film

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science china(Physics,Mechanics & Astronomy) 2020年第7期63卷 89-92页

作者： LiPing Yu DongXue Han JingLi Ren xiaoxiang guo ShaoKang Guan Gang wang henan Academy of Big Data Zhengzhou University.Zhengzhou 450052China College of science Henan University of TechnologyZhengzhou 450001China Laboratory for Microstructures Institute of MaterialsShanghai UniversityShanghai 200444China school of materials science and {3. Zhengzhou UniversityZhengzhou 450001China

Chaos has been well understood in dynamic system, however, how the chaotic behavior occur in jerky flow in material, is still not clear, and is lack of specific chaotic attractor. here the jerky evolution of lateral force and the stair-like fluctuation of lateral displacement are observed for Ni62 Nb3.(at.%) metallic glass film during nanoscratch process. This jerky flow is investigated by using the largest Lyapunov exponent, Kolmogorov entropy and fractal dimension, and chaotic behavior of lateral force-time and normal displacement-lateral displacement sequences is verified. In addition to time series analysis, it is found that jerk equation can be used to describe the jerky flow of the metallic-glass film during nanoscratch. More importantly, unambiguous chaotic attractor is presented by jerky dynamics using "jerk"-singularities, namely the total change rate of lateral force relative to scratch time. These reveal an inner connection between jerky flow and jerky dynamics in nanoscratch of a metallic-glass film.

关键词： metallic-glass film jerky flow jerky dynamics chaos

Influence of nano-scaled dispersed second phase on substructure of deformed dispersion strengthened copper alloy

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Journal of Central South university of Technology 2005年第z1期12卷 50-53页

作者： CheNG Jian-yi wang Ming-pu CAO Jian-guo ZHAO Xue-long guo Ming-xing school of materials science and {3. Jiujiang University Jiujiang 332005 China school of Metallurgy science and engineering Central South University Changsha 410083 China hailiang Group Co. Ltd Zhuji 311835 China School of Materials Science and Engineering Central South University Changsha 410083 China Hailiang Group Co. Ltd Zhuji 311835 China Hailiang Group Co. Ltd Zhuji 311835 China School of Materials Science and Engineering Central South University Changsha 410083 China

The deformation behavior of dispersion strengthened copper alloy Cu-Al2O3.was studied by TEM. The results show that nano-scaled dispersed second phase not only increases dislocation density in matrix, but also has an important influence on the dislocation substructure. The presence of fine dispersed Al2 O3.particles results in a uniform and random dislocation distribution in matrix copper and causes the difficulty in formation of dislocation cell structure and the decrease in the amount of cell structure during deformation. Deformation gives rise to much more dislocations and dislocation cells form more difficultly and the decrease in the cell size with the increase of dispersion degree.

关键词： dispersed phase particle dispersion strengthened copper alloy deformation substructure

纳米器件空间辐射效应机理和模拟试验技术研究进展

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科学通报 2018年第13期63卷 1211-1222页

作者：陈伟刘杰马晓华郭刚赵元富郭晓强罗尹虹姚志斌丁李利王晨辉陈荣梅何宝平赵雯张凤祁马武英翟鹏飞王祖军刘天奇郭红霞刘建德杨海亮胡培培丛培天李宗臻西北核技术研究所强脉冲辐射环境模拟与效应国家重点实验室西安710024 中国科学院近代物理研究所兰州730000 西安电子科技大学微电子学院西安710126 中国原子能研究院抗辐照应用技术创新中心北京102413 北京微电子技术研究所北京100076 清华大学工程物理系北京100084

电子器件空间辐射效应是影响航天器在轨长期可靠运行的重要因素之一,一直是国际上抗辐射加固技术领域研究的热点和难点.高可靠、高集成度、高性能、低功耗、低成本是未来新一代先进电子系统发展的必然要求,采用更高性能的抗辐射加固纳... 详细信息

电子器件空间辐射效应是影响航天器在轨长期可靠运行的重要因素之一,一直是国际上抗辐射加固技术领域研究的热点和难点.高可靠、高集成度、高性能、低功耗、低成本是未来新一代先进电子系统发展的必然要求,采用更高性能的抗辐射加固纳米器件是必然的趋势.本文在深入调研国内外研究现状的基础上,分析了纳米器件辐射效应面临的新问题.纳米工艺存在着很多不同于大尺寸工艺的特点,沟道长度缩小到十几个纳米,栅氧化层等效厚度小于1 nm.在工艺上引入了纵向逆掺杂阱或横向晕环掺杂技术,以降低栅极诱导漏极漏电效应;在材料上引入了多元半导体材料、应变硅、锗硅、高k栅介质、金属栅极等,以降低器件功耗;在结构上引入了三维Fin FET结构,以增强栅的控制能力.这种趋于物理极限的工艺特点、新材料和新结构的采用产生了许多新的辐射效应现象和机制,模拟试验技术更加复杂,给抗辐射加固技术研究带来了新的挑战.本文综述了纳米器件辐射效应的研究现状和趋势,重点针对28 nm及以下特征工艺纳米器件辐射效应研究及模拟试验的需求,提出了需要研究的科学问题和关键技术,希望能为纳米器件抗辐射加固与空间应用提供参考.

关键词：纳米器件空间辐射效应抗辐射加固模拟试验