检索结果-南通市图书馆

Microstructure and mechanical properties of 3D printed ceramics with different vinyl acetate contents

Rare Metals 2021年第11期40卷 3241-3250页

作者： He Li Yong-Sheng Liu Yan-Song Liu Qing-Feng Zeng Jing-Jing Liang Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’an 710072China npu-sas joint research center of advanced ceramics Northwestern Polytechnical UniversityXi’an 710072China Institute of Metal research Chinese Academy of SciencesShenyang 110016China

Stereolithography(SL)-based three-dimensional(3D) printing technique is an efficient method for the fabrication of alumina *** alumina slurry is difficult to obtain due to the barrier between hydrophilic alumina and oleophilic *** not only requires that the ceramic slurry possessed low viscosity and uniformity,but also requires that the slurry could complete the photocuring *** this study,vinyl acetate was added in the ceramic slurry as a bridge to connect alumina and resin,and the effects of vinyl acetate content on the microstructure and mechanical properties of the alumina ceramics were systematically *** results showed that the alumina ceramics were composed of three types of particles which included large aggregates,individual particles,and long-columnshaped *** shrinkage,bulk density,and crystallite size of the ceramics increased with the increase in vinyl acetate *** open porosity decreased with the increase in vinyl acetate *** flexural strength of the ceramics first increased and subsequently decreased with the increase in vinyl acetate *** shrinkage in Z direction was much greater than that in X or Y *** on the above results,the optimum vinyl acetate content for alumina slurry was 10 wt%,which resulted in sintered ceramic with the shrinkage of 15.6% in X direction,13.5% in Ydirection,21.9% in Z direction,bulk density of 1.9 g·cm^(-3),open porosity of 50.1%,and flexural strength of 24.4 *** sintered ceramics satisfy the requirement of alumina ceramic cores.

关键词： Stereolithography Alumina ceramics Vinyl acetate Microstructure Mechanical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mechanistic insight into the synergy between nickel single atoms and nanoparticles on N-doped carbon for electroreduction of CO2

引用

Journal of Energy Chemistry 2025年第1期100卷 327-336页

作者： Mingdong Sun Wenwen Guan Cailing Chen Chao Wu Xiaoling Liu Biao Meng Tao Chen Yu Han Jun Wang Shibo Xi Yu Zhou State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Nanjing Tech University advanced Membranes and Porous Materials center Physical Sciences and Engineering Division King Abdullah University of Science and Technology Institute of Sustainability for Chemicals Energy and Environment A*STAR (Agency for Science Technology and Research) College of Materials Science and Engineering Sichuan University

The synergy of single atoms （sas） and nanoparticles （NPs） has demonstrated great potential in promoting the electrocatalytic carbon dioxide reduction reaction （CO2RR）;however,the rationalization of the sas/NPs proportion remains one challenge for the catalyst ***,a Ni2+-loaded porous poly（ionic liquids）(PIL) precursor synthesized through the free radical self-polymerization of the ionic liquid monomer,1-allyl-3-vinylimidazolium chloride,was pyrolyzed to prepare the Ni,N co-doped carbon materials,in which the proportion of Ni sas and NPs could be facilely modulated by controlling the annealing *** catalyst Ni-NC-1000 with a moderate proportion of Ni sas and NPs exhibited high efficiency in the electrocatalytic conversion of CO2into *** Ni K-edge X-ray absorption near-edge structure （XANES） spectra and theoretical calculations were conducted to gain insight into the synergy of Ni sas and *** charge transfer from Ni NPs to the surrounding carbon layer and then to the Ni sas resulted in the electron-enriched Ni sas active *** the electroreduction of CO2,the coexistence of Ni sas and NPs strengthened the CO2activation and the affinity towards the key intermediate of*COOH,lowering the free energy for the potential-determining*CO2→*COOH step,and therefore promoted the catalysis efficiency.

关键词： Single atom catalyst Synergy effect Carbon catalyst Electrocatalysis

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Microstructure and properties of 3D-printed alumina ceramics with different heating rates in vacuum debinding

引用

Rare Metals 2020年第5期39卷 577-588页

作者： He Li Yong-Sheng Liu Yan-Song Liu Qing-Feng Zeng Ke-Hui Hu Jing-Jing Liang Zhi-Gang Lu Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi'an 710072China npu-sas joint research center of advanced ceramics Northwestern Polytechnical UniversityXi'an 710072China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China State Key Laboratory of Tribology Tsinghua University Beijing 100084China Institute of Metal research Chinese Academy of Sciences Shenyang 110016China

The effect of heating rates during vacuum debinding on the microstructure and mechanical properties of alumina ceramics are discussed in this *** threedimensional(3D)-printed alumina ceramics examined in this study were found to have a layered structure,and interlayer spacing increased as the heating rate increased The pore diameter,shrinkage,flexural strength and hardness were found to decrease as the heating rate increased due to weak interfacial bonding between alumina particles Shrinkage was found to be much larger along the Z direction than along the X or Y directions due to the layer-bylayer forming mode during 3D printing.0.5°C·min-1is considered the optimum heating rate,yielding ceramics with interlayer spacing of 0.65 lm,shrinkage of 2.6%2.3%and 4.0%along the X,Y and Z directions,respectively,flexural strength of 27.5 MPa,hardness of29.8 GPa,Vickers hardness of HV 266.5,pore diameter of356.8 nm,bulk density of 2.5 g·cm-3,and open porosity of38.4%.The debinding procedure used in this study could be used to produce a high-quality ceramic which can be used for fabricating alumina ceramic cores.

关键词： Heating rate Vacuum debinding Alumina ceramics Three-dimensional(3D)printing Stereolithography

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of sintering temperature in argon atmosphere on microstructure and properties of 3D printed alumina ceramic cores

引用

Journal of advanced ceramics 2020年第2期9卷 220-231页

作者： He LI Yongsheng LIU Yansong LIU Qingfeng ZENG Kehui HU Zhigang LU Jingjing LIANG Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’anShaanxi 710072China npu-sas joint research center of advanced ceramics Northwestern Polytechnical UniversityXi’anShaanxi 710072China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Institute of Metal research Chinese Academy of SciencesShenyang 110016China

Alumina ceramics with different sintering temperatures in argon atmosphere were obtained using stereolithography-based 3D *** effects of sintering temperature on microstructure and physical and mechanical properties were *** results show that the average particle size,shrinkage,bulk density,crystallite size,flexural strength,Vickers hardness,and nanoindentation hardness increased with the increase in sintering temperature,whereas the open porosity decreased with increasing sintering *** change was observed in phase composition,chemical bond,atomic ratio,and surface *** the sintered samples,the shrinkage in Z direction is much greater than that in X or Y *** optimum sintering temperature in argon atmosphere is 1350℃with a shrinkage of 3.0%,3.2%,and 5.5%in X,Y,and Z directions,respectively,flexural strength of 26.7 MPa,Vickers hardness of 198.5 HV,nanoindentation hardness of 33.1 GPa,bulk density of 2.5 g/cm^3,and open porosity of 33.8%.The optimum sintering temperature was 70℃higher than that sintering in air atmosphere when achieved the similar properties.

关键词： sintering temperature argon atmosphere alumina ceramics microstructure stereolithography

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Balancing flexural strength and porosity in DLP-3D printing Al_(2)O_(3)cores for hollow turbine blades

引用

Journal of Materials Science & Technology 2022年第9期104卷 19-32页

作者： Qiaolei Li Xiaolong An Jingjing Liang Yongsheng Liu Kehui Hu Zhigang Lu Xinyan Yue Jinguo Li Yizhou Zhou Xiaofeng Sun School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-changxu Innovation center for advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Space Manufacturing Technology(CAS Key Lab) Beijing 100094China npu-sas joint research center of advanced ceramics Northwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China

High porosity and high strength are usually mutually exclusive in the preparation of ceramic ***,high porosity and flexural strength are required for the preparation of complex ceramic cores for hollow turbine *** this study,Al_(2)O_(3)cores with high porosity and high flexural strength were successfully prepared using digital light processing(DLP)3 D printing *** influence of sintering temperature on the microstructure,pore evolution,and flexural strength of the cores were *** an increase in the sintering temperature,the porosity of the ceramic cores first increased and then decreased,reaching a maximum value of 35%at 1400℃.The flexural strength increased with the increase in sintering temperature,but at 1400℃the incremental enhancement of flexural strength was *** with the core service requirements and core performance,this study selected 1400℃(open porosity of 35.1%and flexural strength of 20.3 MPa)as the optimal sintering temperature for the DLP-3 D printed Al_(2)O_(3)core.

关键词： 3D printing Ceramic cores Flexural strength Porosity Sintering temperature

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Pressure-driven symmetry breaking and electron disproportionation of the trigonal Nb_(3)cluster in Nb_(3)Cl_(8)

引用

Science China(Physics,Mechanics & Astronomy) 2022年第7期65卷 153-158页

作者： Zimin Jiang Dequan Jiang Yiming Wang Chen Li Ke Liu Ting Wen Fuyang Liu Zhengyang Zhou Yonggang Wang center for High Pressure Science and Technology advanced research(HPSTAR) Beijing 100094China Shanghai Institute of ceramics Chinese Academy of SciencesShanghai 201899China

Symmetry breaking of metal cluster-based strongly correlated systems can give rise to collective ***,the twodimensional Nb_(3) cluster compound Nb_(3)Cl_(8) is shown to suffer dramatic symmetry breaking and electron disproportionation under compression.A structural phase transition from trigonal P–3m1 to monoclinic C2/m is observed near 8 GPa with the three-fold symmetry *** disproportionation occurs on Nb_(3) clusters from delocalized Nb^(8/3+)Nb^(8/3+)Nb^(8/3+)to localized Nb^(3+)Nb^(3+)Nb^(2+),which results in a subtle bandgap discontinuity,as evidenced by electrical transport and UV-Vis absorption measurements.

关键词： Nb_(3)Cl_(8) symmetry breaking electron disproportionation layered semiconductor high pressure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Tuning mechanical and electrical performances of B_(4)C-TiB_(2)ceramics in a two-step spark plasma sintering process

引用

Journal of advanced ceramics 2024年第4期13卷 518-528页

作者： Jun Zhao Xingshuo Zhang Zongning Ma Dong Wang Xing Jin Songlin Ran advanced ceramics research center School of Materials Science and EngineeringAnhui University of TechnologyMaanshan 243002China Anhui Engineering research center for High Efficiency Intelligent Photovoltaic Module Chaohu UniversityHefei 238024China

B_(4)C–TiB_(2)is an advanced electrically conductive ceramic with excellent mechanical and electrical discharge machinable *** is challenging and rewarding to achieve highly conductive and hard B_(4)C–TiB_(2)composites at a minimum content of conductive TiB2 that has inferior hardness but double specific gravity of the B_(4)C matrix.A novel strategy was used to construct conductive networks in B_(4)C‒15 vol%TiB2 composite ceramics with B_(4)C,TiC,and amorphous B as raw materials by a two-step spark plasma sintering *** influences of particle size matching between B_(4)C and TiC on the conducting of the strategy and the microstructure were discussed based on the selective matrix grain growth *** mechanical and electrical properties were also systematically *** B_(4)C–15 vol%TiB2 composite ceramic prepared from 10.29µm B_(4)C and 0.05µm TiC powders exhibited a perfect three-dimensional interconnected conductive network with a maximum electrical conductivity of 4.25×10^(4)S/m,together with excellent mechanical properties including flexural strength,Vickers hardness,and fracture toughness of 691±58 MPa,30.30±0.61 GPa,and 5.75±0.32 MPa·m^(1/2),respectively,while the composite obtained from 3.12µm B_(4)C and 0.8µm TiC powders had the best mechanical properties including flexural strength,Vickers hardness,and fracture toughness of 827±35 MPa,32.01±0.51 GPa,and 6.45±0.22 MPa·m^(1/2),together with a decent electrical conductivity of 0.65×10^(4)S/m.

关键词： B_(4)C-TiB_(2) mechanical properties electrical conductivity conductive network

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fabrication and properties of non-stoichiometric Tb_(2)(Hf_(1-x)Tb_(x))_(2)O_(7-x)magneto-optical ceramics

引用

Journal of advanced ceramics 2022年第5期11卷 784-793页

作者： Lixuan ZHANG Xiaoying LI Dianjun HU Ziyu LIU Tengfei XIE Lexiang WU Zhaoxiang YANG Jiang LI Transparent ceramics research center Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 201899China center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBejing 100049China

Non-stoichiometric Tb_(2)(Hf_(1-x)Tb_(x))_(2)O_(7-x)(x=-0.07-0.45)magneto-optical ceramics were fabricated by solid-state reactive sintering in vacuum combined with hot isostatic pressing(HIP)posttreatment without any sintering *** phase composition,densification process,microstructure,optical transmittance,and Verdet constant of Tb_(2)(Hf_(1-x)Tb_(x))_(2)O_(7-x)ceramics were *** in-line transmittance of(Tb_(0.93)Hf_(0.04))_(2)Hf_(2)O_(7.07)ceramics with a thickness of 2.0 mm reaches 74.6%at 1064 *** Verdet constant of Tb_(2)(Hf_(1-x)Tb_(x))_(2)O_(7-x)ceramics is-153.4,-155.8,and-181.2 rad/(T-m)at the wavelength of 633 nm when x=-0.07,0,and 0.1,*** Verdet constant increases with the increase of Tb content,and these values are higher than that of the commercial Tb_(3)Ga_(5)O_(12) crystal,indicating that non-stoichiometric Tb_(2)(Hf_(1-x)Tb_(x))_(2)O_(7-x)ceramics have a great potential for the application in Faraday isolators.

关键词： magneto-optical ceramics Tb_(2)(Hf_(1-x)Tb_(x))_(2)O_(7-x)ceramics reactive sintering Verdet constant

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of interfacial residual stress on mechanical behavior of SiC_(f)/SiC composites

引用

Journal of advanced ceramics 2022年第1期11卷 94-104页

作者： Xiaowu CHEN Guofeng CHENG Jinshan YANG Jianbao HU Chunjin LIAO Xiangyu ZHANG Shaoming DONG State Key Laboratory of High Performance ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Structural ceramics and Composites Engineering research center Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Analysis and Testing center for Inorganic Materials Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China

Layer-structured interphase,existing between reinforcing fiber and ceramics matrix,is an indispensable constituent for fiber-reinforced ceramic composites due to its determinant role in the mechanical behavior of the ***,the interphase may suffer high residual stress because of the mismatch of thermal expansion coefficients in the constituents,and this can exert significant influence on the mechanical behavior of the ***,the residual stress in the boron nitride(BN)interphase of continuous SiC fiber-reinforced SiC composites was measured using a micro-Raman *** effects of the residual stress on the mechanical behavior of the composites were investigated by correlating the residual stress with the mechanical properties of the *** results indicate that the residual stress increases from 26.5 to 82.6 MPa in tension as the fabrication temperature of the composites rises from 1500 to 1650℃.Moreover,the increasing tensile residual stress leads to significant variation of tensile strain,tensile strength,and fiber/matrix debonding mode of the *** sublayer slipping of the interphase caused by the residual stress should be responsible for the transformation of the mechanical *** work can offer important guidance for residual stress adjustment in fiber-reinforced ceramic composites.

关键词： ceramic matrix composites Raman spectroscopy mechanical properties residual stress

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fabrication and mechanical behavior of 2D-C_(f)/Ta_(x)Hf_(1−x)C–SiC composites by a low-temperature and highly-efficient route

引用

Journal of advanced ceramics 2023年第10期12卷 1961-1972页

作者： Xuegang Zou Dewei Ni Bowen Chen Feiyan Cai Le Gao Ping He Yusheng Ding Xiangyu Zhang Shaoming Dong State Key Laboratory of High-Performance ceramics&Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Structural ceramics and Composites Engineering research center Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China University of Chinese Academy of Sciences Beijing 100049China Hangzhou Institute for advanced Study University of Chinese Academy of SciencesHangzhouChina

C_(f)/Ta_(x)Hf_(1−x)C–SiC composites are ideal thermal structural materials for service under extreme conditions of hypersonic ***,how to synthesize TaxHf1-xC powders and efficiently fabricate C_(f)/Ta_(x)Hf_(1−x)C–SiC composites still faces some ***,mechanical properties and thermophysical properties of Ta_(x)Hf_(1−x)C vary with the composition,but not ***-depth analysis of mechanical behaviors of the C_(f)/Ta_(x)Hf_(1−x)C–SiC composites is extremely important for their development and *** this study,the Ta_(x)Hf_(1−x)C powders(x=0.2,0.5,0.8)were successfully synthesized via solid solution of TaC and HfC at a relatively low temperature of 1800℃,with a small amount of Si as an ***,the efficient fabrication of 2D-C_(f)/Ta_(x)Hf_(1−x)C–SiC composites was achieved by slurry impregnation and lamination(SIL)combined with precursor infiltration and pyrolysis(PIP).In addition,the mechanical behavior of the composites was investigated *** is demonstrated that the composites present remarkable non-brittle fractures,including a large number of fiber pull out and interphase ***,the fracture failure involves a complex process of microcrack generation and propagation,matrix cracking,and layer ***,the interfacial bonding between the fibers and the matrix is enhanced as the Ta∶Hf ratio decreases from 4∶1 to 1∶*** a result,C_(f)/Ta_(0.2)Hf_(0.8)C–SiC composites exhibit exceptional flexural strength of 437±19 MPa,improved by 46%compared with C_(f)/Ta_(0.8)Hf_(0.2)C–SiC(299±19 MPa).This study provides a new perception of design and fabrication of ultra-high-temperature ceramic(UHTC)matrix composites with high performance.

关键词： mechanical properties microstructure fabrication 2D-C_(f)/Ta_(x)Hf_(1−x)C-SiC composites

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：