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Microstructure characteristics and thermodynamic properties of A357-SiCp/A357 layered composites prepared by semi-solid vacuum stirring suction casting
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作者 Zhen-lin Zhang Ying Xiao +3 位作者 Jun Xu Feng-liang Tan Li Wang Min He 《China Foundry》 SCIE CAS CSCD 2023年第2期108-114,共7页
A357-SiCp/A357 layered composites were prepared using a semi-solid vacuum stirring suction casting method.The microstructures,mechanical properties,and thermal conductivities of the composites fabricated under differe... A357-SiCp/A357 layered composites were prepared using a semi-solid vacuum stirring suction casting method.The microstructures,mechanical properties,and thermal conductivities of the composites fabricated under different suction casting processes were compared.Additionally,the microstructural evolution characteristics and performance enhancement mechanism of the A357-SiCp/A357 layered composites were discussed.The results demonstrate that suction casting at 610°C with a low solid phase ratio can significantly enhance the material density and reduce the agglomeration of SiCp.The A357-SiC_(p)/A357 interface is clear and straight with good bonding.With an increase in the suction casting temperature,the bending resistance and thermal conductivity of the A357-SiC_(p)/A357 layered composites exhibit a trend of significantly increase at first and then slowly decrease owing to casting defects,interface bonding,and SiCp distribution.Compared with SiCp/A357 composites,the bending strength,deflection,and thermal conductivity of the A357-SiCp/A357 layered composites increase from 257 MPa,1.07 mm,and 155.72 W·(m·K)^(-1) to 298 MPa,2.1 mm,and 169.86 W·(m·K)^(-1),respectively.This study provides a reference for improving the rheological casting of aluminum matrix layered composites. 展开更多
关键词 SEMI-SOLID vacuum stirring suction casting SiCp/A357 layered composites thermodynamic properties rheological casting
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In-situ additive manufacturing of high strength yet ductility titanium composites with gradient layered structure using N_(2)
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作者 Yunmian Xiao Changhui Song +4 位作者 Zibin Liu Linqing Liu Hanxiang Zhou Di Wang Yongqiang Yang 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第3期387-409,共23页
It has always been challenging work to reconcile the contradiction between the strength and plasticity of titanium materials.Laser powder bed fusion(LPBF) is a convenient method to fabricate innovative composites incl... It has always been challenging work to reconcile the contradiction between the strength and plasticity of titanium materials.Laser powder bed fusion(LPBF) is a convenient method to fabricate innovative composites including those inspired by gradient layered materials.In this work,we used LPBF to selectively prepare Ti N/Ti gradient layered structure(GLSTi)composites by using different N_(2)–Ar ratios during the LPBF process.We systematically investigated the mechanisms of in-situ synthesis Ti N,high strength and ductility of GLSTi composites using microscopic analysis,TEM characterization,and tensile testing with digital image correlation.Besides,a digital correspondence was established between the N_(2) concentration and the volume fraction of LPBF in-situ synthesized Ti N.Our results show that the GLSTi composites exhibit superior mechanical properties compared to pure titanium fabricated by LPBF under pure Ar.Specifically,the tensile strength of GLSTi was more than 1.5times higher than that of LPBF-formed pure titanium,reaching up to 1100 MPa,while maintaining a high elongation at fracture of 17%.GLSTi breaks the bottleneck of high strength but low ductility exhibited by conventional nanoceramic particle-strengthened titanium matrix composites,and the hetero-deformation induced strengthening effect formed by the Ti N/Ti layered structure explained its strength-plasticity balanced principle.The microhardness exhibits a jagged variation of the relatively low hardness of 245 HV0.2 for the pure titanium layer and a high hardness of 408 HV0.2 for the N_(2) in-situ synthesis layer.Our study provides a new concept for the structure-performance digital customization of 3D-printed Ti-based composites. 展开更多
关键词 laser powder bed fusion layered structure composites in-situ synthesis TiN strength-plasticity synergy
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Intercalated MXene-based layered composites:Preparation and application 被引量:2
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作者 Shumeng Wu He Wang +4 位作者 Li Li Meixia Guo Zhichong Qi Qingyou Zhang Yanmei Zhou 《Chinese Chemical Letters》 SCIE CAS CSCD 2020年第4期961-968,共8页
Combining high conductivity,hydrophilicity and excellent electrochemical perfo rmance in one,MXe nes have attracted increasing attention since their inception.However,easy to stack caused by the van der Waals’force b... Combining high conductivity,hydrophilicity and excellent electrochemical perfo rmance in one,MXe nes have attracted increasing attention since their inception.However,easy to stack caused by the van der Waals’force between the layers limits their practical application.Fortunately,intercalating other substances between layers of MXe nes and getting intercalated MXene-based layered composites(IMLCs)with open structure can improve their physical and chemical properties effectively.Larger available surface helps expose more active sites and enlarged layer spacing facilitates ion transport.In addition,other substances fixed in the interlayers by MXenes’two-dimensional confinement effect can produce synergistic effect and expand their applicable range greatly.This review is dedicated to summarizing the preparation methods and applications of IMLCs,emphasizing the advantages of them in the fields of energy storage,catalysis,sensors,electromagnetic interference(EMI)shielding and biomedicine.Furthermore,prospects and further developments in these gratifying fields are also commented. 展开更多
关键词 MXenes layered composites Energy storage CATALYSIS SENSORS EMI shielding BIOMEDICINE
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Height-related magnetoelectric performance of PZT/Ni layered composites
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作者 Zhi-Jun Zuo De-An Pan +4 位作者 Li-Jun Wang Jian-Jun Tian Shen-Gen Zhang Li-Jie Qiao Alex A.Volinsky 《Rare Metals》 SCIE EI CAS CSCD 2017年第7期591-595,共5页
The effect of height on performance of the PZT/Ni cylindrical bilayered magnetoelectric (ME) com- posites was studied in situ in this paper. Multiple resonant peaks appear between 1 and 300 kHz frequency for cyl- in... The effect of height on performance of the PZT/Ni cylindrical bilayered magnetoelectric (ME) com- posites was studied in situ in this paper. Multiple resonant peaks appear between 1 and 300 kHz frequency for cyl- inders of different heights. The first resonance frequency does not change with the cylinder height decreasing, but the second and the third resonant frequencies increase. The first three resonant modes radial, first-order height are attributed to the cylinder resonance, and second-order height resonance, respectively. The appropriate size and resonance frequency were chosen to obtain the highest ME voltage coefficient when designing cylindrical bilayered magnetoelectric devices. This article provides reference to design cylindrical magnetoelectric devices. 展开更多
关键词 Cylindrical layered composites HEIGHT Resonant mode Demagnetization factor
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ELASTIC SH WAVE PROPAGATION IN PERIODIC LAYERED COMPOSITES WITH A PERIODIC ARRAY OF INTERFACE CRACKS 被引量:2
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作者 Zhizhong Yan Chunqiu Wei Chuanzeng Zhang 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2015年第5期453-463,共11页
The interaction of anti-plane elastic SH waves with a periodic array of interface cracks in a multi-layered periodic medium is analyzed in this paper. A perfect periodic structure without interface cracks is first stu... The interaction of anti-plane elastic SH waves with a periodic array of interface cracks in a multi-layered periodic medium is analyzed in this paper. A perfect periodic structure without interface cracks is first studied and the transmission displacement coefficient is obtained based on the transfer matrix method in conjunction with the Bloch-Floquet theorem. This is then generalized to a single and periodic distribution of cracks at the center interface and the result is compared with that of perfect periodic cases without interface cracks. The dependence of the transmission displacement coefficient on the frequency of the incident wave, the influences of material combination, crack configuration and incident angle are discussed in detail. Compared with the corresponding perfect periodic structure without interface cracks, a new phenomenon is found in the periodic layered system with a single and periodic array of interface cracks. 展开更多
关键词 layered composite transmission coefficient interface crack transfer matrix method
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Aluminum matrix composites reinforced by molybdenum-coated carbon nanotubes 被引量:9
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作者 Jun-hui Nie Cheng-chang Jia Na Shi Ya-feng Zhang Yi Li XianJia 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2011年第6期695-702,共8页
To extend the application of carbon nanotubes (CNTs) and explore novel aluminum matrix composites,CNTs were coated by molybdenum layers using metal organic chemical vapor deposition,and then Mo-coated CNT (Mo-CNT)... To extend the application of carbon nanotubes (CNTs) and explore novel aluminum matrix composites,CNTs were coated by molybdenum layers using metal organic chemical vapor deposition,and then Mo-coated CNT (Mo-CNT)/Al composites were prepared by the combination processes of powder mixing and spark plasma sintering.The influences of powder mixing and Mo-CNT content on the mechanical properties and electrical conductivity of the composites were investigated.The results show that magnetic stirring is better than mechanical milling for mixing the Mo-CNTs and Al powders.The electrical conductivity of the composites decreases with increasing Mo-CNT content.When the Mo-CNT content is 0.5wt%,the tensile strength and hardness of Mo-CNT/Al reach their maximum values.The tensile strength of 0.5wt% Mo-CNT/Al increases by 29.9%,while the electrical conductivity only decreases by 7.1%,relative to sintered pure Al.The phase analysis of Mo-CNT/Al composites reveals that there is no formation of Al carbide in the composites. 展开更多
关键词 carbon nanotubes aluminum matrix composites molybdenum layer mechanical properties electrical conductivity
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Love Waves in Layered Graded Composite Structures with Imperfectly Bonded Interface 被引量:1
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作者 LIU Hua YANG Jia-ling LIU Kai-xin 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2007年第3期210-214,共5页
Theoretical analysis and numerical calculations of Love wave propagation in layered graded composites with imperfectly bonded interface are described in this paper. On the basis of WKB method, the approximate analytic... Theoretical analysis and numerical calculations of Love wave propagation in layered graded composites with imperfectly bonded interface are described in this paper. On the basis of WKB method, the approximate analytic solutions for Love waves are obtained. By the interface shear spring model, the dispersion relations for Love waves in layered graded composite structures with rigid, slip, and imperfectly bonded interfaces are given, and the effects of the interface conditions on the phase velocities of Love waves in SiC/Al layered graded composites are discussed. Numerical analysis shows that the phase velocity decreases when the defined flexibility parameter is greater. For the general imperfectly bonded interface, the phase velocity changes in the range of the velocities for the rigid and slip interface conditions. 展开更多
关键词 Love wave layered graded composites WKB method dispersion relation
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A Study on a Magnesium-Based Layered Composite Used as a Flame Retardant for Phenolic Epoxy Resins
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作者 Hongxiang Liu Neng Xiong +2 位作者 Songli Wang Wei Zhang Bo Yong 《Fluid Dynamics & Materials Processing》 EI 2022年第3期549-561,共13页
The effects of a magnesium-based layered composite on the flammability of a phenolic epoxy resin(EP)are studied.In order to produce the required composite material,first,magnesium hydroxide,aluminum salt and deionized... The effects of a magnesium-based layered composite on the flammability of a phenolic epoxy resin(EP)are studied.In order to produce the required composite material,first,magnesium hydroxide,aluminum salt and deionized water are mixed into a reactor according to a certain proportion to induce a hydrothermal reaction;then,the feed liquid is filtered out using a solid-liquid separation procedure;finally,the material is dried and crushed.In order to evaluate its effects on the flammability of the EP,first,m-phenylenediamine is added to EP and vacuum defoamation is performed;then,EP is poured into a polytetrafluoroethylene mold,cooled to room temperature and demoulded;finally,the magnesium-based layered composite is added to EP,and its flame retardance is characterized by thermogravimetric analysis,limiting oxygen index and cone calorimetry.The X-ray diffraction patterns show that the baseline of magnesium-based layered composite is stable and the front shape is sharp and symmetrical when the molar ratio of magnesium to aluminium is 3.2:1;with the addition of magnesium-based layered composite,the initial pyrolysis temperature of EP of 10%,15%and 30%magnesium-based layered composite decreases to 318.2°C,317.9°C and 357.1°C,respectively.After the reaction,the amount of residual carbon increases to 0.1%,3.45%and 8.3%,and the limiting oxygen index increases by 28.3%,29.1%and 29.6%,respectively.The maximum heat release rate of cone calorimeter decreases gradually.The optimum molar ratio of Mg:Al for green synthesis is 3.2:1,and the NO_(3)-intercalated magnesium-based layered composite has the best flame retardance properties. 展开更多
关键词 Phenolic epoxy resin layered composite green synthesis flame retardance anion intercalation
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Preparation and characterization of diamond film on Cu substrate using Cu-diamond composite interlayer 被引量:1
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作者 邱万奇 胡志刚 +2 位作者 刘仲武 曾德长 周克崧 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第3期758-763,共6页
Large area diamond films were fabricated on copper substrates by a multi-step process comprised of electroplating Cu-diamond composite layer on Cu substrate, plating a Cu layer to fix the protruding diamond particles,... Large area diamond films were fabricated on copper substrates by a multi-step process comprised of electroplating Cu-diamond composite layer on Cu substrate, plating a Cu layer to fix the protruding diamond particles, and depositing continuous diamond film on composite interlayer by hot-filament chemical vapor deposition (HFCVD). The interface characteristics, internal stress and adhesion strength were investigated by scanning electron microscopy, Raman analysis and indentation test. The results show that the continuous film without cracks is successfully obtained. The microstructure of the film is a mixture of large cubo-octahedron grains grown from homo-epitaxial growth and small grains with (111) apparent facets grown from lateral second nuclei. The improved adhesion between diamond film and substrate results from the deep anchoring of the diamond particles in the Cu matrix and the low residual stress in the film. 展开更多
关键词 diamond film composites layer ELECTROPLATING ADHESION chemical vapor deposition
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Formation mechanism of bimetal composite layer between LCS and HCCI 被引量:3
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作者 Yong-chang Zhu Zun-jie Wei +2 位作者 Shou-fan Rong Hong-wei Wang Chun-ming Zou 《China Foundry》 SCIE 2016年第6期396-401,共6页
A low carbon steel (LCS)/high chromium white cast iron (HCCI) bimetal wear plate about 20 mm in thickness was prepared by liquid-liquid bimetal composite casting technology to substitute for the welding wear plate... A low carbon steel (LCS)/high chromium white cast iron (HCCI) bimetal wear plate about 20 mm in thickness was prepared by liquid-liquid bimetal composite casting technology to substitute for the welding wear plate. A clear and distinguishable composite layer between the LCS and the HCCI was detected with SEM, and the composition and phase were analyzed through EDS and XRD. The composite layer was composed of three sublayers from the LCS to the HCCI: pearlite transition layer, composite layer, and HCCI transition layer. The Vickers hardness from the pearlite transition layer to the HCCl transition layer was 360 HV to 855 HV. The austenite grows as dendrites between the composite layer and the HCCI transition layer under constitutional undercooling. A large amount of C and Cr, and a small amount of Si and Mn dissolve in the matrix. Granular Cr7C3 is uniformly distributed. Due to the solute redistribution at the solid-liquid interface, the primary austenite grows from planar to cellular and finally to the distinct dendrite crystals. The dendrite crystals have an obvious growth direction perpendicular to the composite layer. 展开更多
关键词 liquid-liquid composite casting bimetal wear plate composite layer dendritic austenite
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Microstructure of Ni /WC Surface Composite Layer on Gray Iron Substrate 被引量:2
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作者 杨贵荣 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第5期861-866,共6页
The surface infiltrated composite (Ni/WC) layers on gray iron substrate were fabricated through a vacuum infiltration casting technique (VICT) using Ni-based composite powder with different WC particles content as... The surface infiltrated composite (Ni/WC) layers on gray iron substrate were fabricated through a vacuum infiltration casting technique (VICT) using Ni-based composite powder with different WC particles content as raw materials.The microstructures of surface infiltrated composite layer,the interface structures between surface composite layer and the substrate,the changes of macro-hardness with the increasing of WC content and the micro-hardness distribution are investigated.The infiltrated composite layer includes a surface composite layer and a transition layer,and the thickness of the transition layer decreases with the increasing content of WC.The thickness of transition layer with 20%WC content in the surface infiltrated composite layer was 170 μm which was the thickest for all transition layers with different WC content.The surface composite layer was mainly composed of WC,W2C,FeB and NiB,along with Ni-Cr-Fe,Ni (Cr) solid solution,Ni (Si) solid solution and Ni (Fe) solid solution.The transition layer was composed of Ni (Cr) solid solution,Ni (Fe) solid solution,Ni (Si) solid solution,Fe (Ni) solid solution and eutectic.The surface macro-hardness and micro-hardness of the infiltrated layer had been evaluated.The macro-hardness of the surface composite layer decreases with the WC content increasing,and the average macro-hardness is HRC60.The distribution of micro-hardness presents gradient change.The average micro-hardness of the infiltrated layer is about HV1000. 展开更多
关键词 Ni/WC surface composite layer vacuum infiltration casting technique gray iron substrate MICROSTRUCTURE hardness of the infiltrated composite layer
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Research on quantum well intermixing of 680 nm AlGaInP/GaInP semiconductor lasers induced by composited Si-Si_(3)N_(4) dielectric layer 被引量:3
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作者 Tianjiang He Suping Liu +4 位作者 Wei Li Cong Xiong Nan Lin Li Zhong Xiaoyu Ma 《Journal of Semiconductors》 EI CAS CSCD 2022年第8期46-52,共7页
The optical catastrophic damage that usually occurs at the cavity surface of semiconductor lasers has become the main bottleneck affecting the improvement of laser output power and long-term reliability.To improve the... The optical catastrophic damage that usually occurs at the cavity surface of semiconductor lasers has become the main bottleneck affecting the improvement of laser output power and long-term reliability.To improve the output power of 680 nm AlGaInP/GaInP quantum well red semiconductor lasers,Si-Si_(3)N_(4)composited dielectric layers are used to induce its quantum wells to be intermixed at the cavity surface to make a non-absorption window.Si with a thickness of 100 nm and Si_(3)N_(4)with a thickness of 100 nm were grown on the surface of the epitaxial wafer by magnetron sputtering and PECVD as diffusion source and driving source,respectively.Compared with traditional Si impurity induced quantum well intermixing,this paper realizes the blue shift of 54.8 nm in the nonabsorbent window region at a lower annealing temperature of 600 ℃ and annealing time of 10 min.Under this annealing condition,the wavelength of the gain luminescence region basically does not shift to short wavelength,and the surface morphology of the whole epitaxial wafer remains fine after annealing.The application of this process condition can reduce the difficulty of production and save cost,which provides an effective method for upcoming fabrication. 展开更多
关键词 high power semiconductor laser rapid thermal annealing composited dielectric layer quantum well intermixing optical catastrophic damage nonabsorbent window
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Effect of silicon content on microstructure of Al-Si/SiC_p composite layer cladded on A380 Al alloy by TIG welding process 被引量:1
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作者 Behnam LOTFI Mehdi ROSTAMI Zohreh SADEGHIAN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第9期2824-2830,共7页
Tungsten inert gas(TIG) welding was applied to creating a composite layer on the surface of cast aluminum alloy A380. Different mixtures of Al, Si and SiC powders mixed with sodium silicate solution were pasted on s... Tungsten inert gas(TIG) welding was applied to creating a composite layer on the surface of cast aluminum alloy A380. Different mixtures of Al, Si and SiC powders mixed with sodium silicate solution were pasted on substrates. Surface melting was conducted by TIG welding to produce Al-SiC layer on the surface. Microstructural evolution was investigated by X-ray diffractometry(XRD), optical and scanning electron microscopy(SEM) and elemental microanalysis(EDS). Properties of clad layers were studied by microhardness and sliding wear testing. The results showed a uniform distribution of SiC particles in dendritic aluminum matrix. Addition of excess silicon caused the formation of eutectic crystals and coarse silicon particles in the clad layer which resulted in higher hardness and wear resistance of clad layers. 展开更多
关键词 Al-SiC TIG welding composite clad layer wear resistance
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Highly sensitive and stable SERS probes of alternately deposited Ag and Au layers on 3D SiO2 nanogrids for detection of trace mercury ions 被引量:1
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作者 Yi Tian Han-Fu Wang +6 位作者 Lan-Qin Yan Xian-Feng Zhang Attia Falak Pei-Pei Chen Feng-Liang Dong Lian-Feng Sun Wei-Guo Chu 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第7期497-506,共10页
The hazard of Hg ion pollution triggers the motivation to explore a fast, sensitive, and reliable detection method. Here, we design and fabricate novel 36-nm-thick Ag-Au composite layers alternately deposited on three... The hazard of Hg ion pollution triggers the motivation to explore a fast, sensitive, and reliable detection method. Here, we design and fabricate novel 36-nm-thick Ag-Au composite layers alternately deposited on three-dimensional (3D) periodic SiO2 nanogrids as surface-enhanced Raman scattering (SERS) probes. The SERS effects of the probes depend mainly on the positions and intensities of their localized surface plasmon resonance (LSPR) peaks, which is confirmed by the absorption spectra from finite-difference time-domain (FDTD) calculations. By optimizing the structure and material to maximize the intrinsic electric field enhancement based on the design method of 3D periodic SERS probes proposed, high performance of the Ag-Au/SiO2 nanogrid probes is achieved with the stability further enhanced by annealing. The optimized probes show the outstanding stability with only 4.0% SERS intensity change during 10-day storage, the excellent detection uniformity of 5.78% (RSD), the detection limit of 5.0 × 10-12 M (1 ppt), and superior selectivity for Hg ions. The present study renders it possible to realize the rapid and reliable detection of trace heavy metal ions by developing high- performance 3D periodic structure SERS probes by designing novel 3D structure and optimizing plasmonic material. 展开更多
关键词 surface-enhanced Raman scattering Ag-Au composite layer nanostructure design trace Hg ions detection
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Generation Mechanism of Interfacial Layer and Its Effect on Fe-Cr-Ni/Al-Si-Cu-Ni-Mg Composite Performance 被引量:2
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作者 周灵展 YANG Liming +1 位作者 ZHU Xiurong PENG Yinjiang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第5期1193-1198,共6页
Fe-Cr-Ni/Al-Si-Cu-Ni-Mg composite was taken as the experimental material. The chemical composition of interfacial layer was tested. The generation mechanism and influence of interfacial layer on the composite were ana... Fe-Cr-Ni/Al-Si-Cu-Ni-Mg composite was taken as the experimental material. The chemical composition of interfacial layer was tested. The generation mechanism and influence of interfacial layer on the composite were analyzed. The results indicated that the generation of interfacial layer is sensitive to temperature. Interfacial layer will generate rapidly when temperature reaches 500 ℃ or above. The interfacial layer is mainly composed of Al, Si, Cu, Fe, and Cr, element Ni distributes at the outward of the interfacial layer for the precipitate of Ni later than Si and Cu, and there is almost no diffusion of Ni during the solution treatment. During heat treatment process, unequal quantity changing of metal atom results in disperse or concentrated vacancies or holes near the matrix. The existence of interfacial layer will induce a decrease of compression strength and plasticity at room temperature and an increase of strength at higher temperature comparing with composite without interfacial layer. 展开更多
关键词 Fe-Cr-Ni composite interfacial layer influence
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Preparation and Properties of the Composite Enhancement Layer of Bearing Ring 被引量:2
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作者 Xiaochu Liu Jianfeng Huang +4 位作者 Zhongwei Liang Weifeng Huang Rui Zhu Weilin Gao Jinrui Xiao 《World Journal of Mechanics》 2020年第10期139-153,共15页
In this paper, the NU308 bearing rings were subjected to strengthen grinding treatment (SGT) at ambient temperature. And the running reliabilities of specimens that subjected to SGT and conventional treatment (CT) wer... In this paper, the NU308 bearing rings were subjected to strengthen grinding treatment (SGT) at ambient temperature. And the running reliabilities of specimens that subjected to SGT and conventional treatment (CT) were respectively investigated by testing dynamic properties including the running temperature, vibrations, and surface burning. Moreover, the residual stress, microtopography, and microstructures on the cross-section were respectively tested with residual stress analyzer and field-emission scanning electron microscopy. The results showed that the running reliabilities of the specimen after SGT had been significantly improved with the reduction of running temperature, vibration, and surface burning. Further study showed that the specimen’s surface was filled with disordered micropores after SGT compared to the regular strip texture on the CT specimen’s surface, and the maximum residual compressive stress induced by SGT was about −900 MPa. Moreover, the thickness of the residual compressive stress layer was over 180 µm, while the thickness of severe plastic deformation layer was about 50 µm. 展开更多
关键词 Strengthen Grinding Treatment Conventional Treatment Composite Enhancement Layer Running Reliability
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Finite element analysis and experimental investigation of the hydrostatic extrusion process of deforming two-layer Cu/Al composite
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作者 张朝晖 王富耻 +2 位作者 孙明燕 杨瑞 李树奎 《Journal of Beijing Institute of Technology》 EI CAS 2013年第4期544-549,共6页
A concave die with an equal-strain contour line was used in the hydrostatic extrusion process to deform the two-layer Cu/A1 composite. The extruding process was simulated using the fi- nite element method (FEM). The... A concave die with an equal-strain contour line was used in the hydrostatic extrusion process to deform the two-layer Cu/A1 composite. The extruding process was simulated using the fi- nite element method (FEM). The effect of the friction coefficients on the relative slippage of the contact surfaces between the internal and external metals was investigated, and the stress distribu- tion in the extruded specimen was studied. The simulation results reveal that the relative slippage de- creases with increasing friction coefficient at the contact surface of the two metals. However, the relative slippage increases rapidly with increasing friction coefficient at the contact surface between the specimen and die. No axial tensile stress appears in the plastic deformation zone near the axis, indicating that the inner fracture will not occur in internal metal in the hydrostatic extrusion process as the concave die with equal-strain contour lines is used. The experimental test reveals that the met- allurgical bond is formed between Cu and A1 when the friction coefficient at the surface between the two metals is 0. 3 and the extrusion ratio is 12. 展开更多
关键词 Cu/A1 layered composite hydrostatic extrugion finite element analysis relative slip-page stress distribution
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Surface Infiltrating Composite of Fe-base Metal and Ceramics
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作者 石功奇 丁培道 +1 位作者 周守则 潘复生 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1992年第3期222-224,共3页
1.IntroductionMetal matrix composites consist of afamily of advanced materials which mayhave attractive properties including highstrength,high specific modulus,lowcoefficient of thermal expansion,good wearresistance,a... 1.IntroductionMetal matrix composites consist of afamily of advanced materials which mayhave attractive properties including highstrength,high specific modulus,lowcoefficient of thermal expansion,good wearresistance,and attractive high temperature 展开更多
关键词 cast iron CERAMICS INFILTRATION composite layer
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Surface Characterization of Ni_(64)P_(20)Fe_(16)Amorphous Alloy by X-ray Photoelectron Spectroscopy and Auger Electron Spectroscopy
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作者 姜洪刚 王景唐 丁炳哲 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1992年第3期157-162,共6页
The nature of the native oxides formed on the surface layer of amorphous alloy Ni_(64)P_(20)Fe_(16)has been studied by X-ray photoelectron spectroscopy (XPS)and Auger electron spectroscopy(AES)with depth profiling by ... The nature of the native oxides formed on the surface layer of amorphous alloy Ni_(64)P_(20)Fe_(16)has been studied by X-ray photoelectron spectroscopy (XPS)and Auger electron spectroscopy(AES)with depth profiling by ion bombardment.There are great distinctions in compositions and chemical states between the surface layer and the bulk.The main constituents Ni,P and Fe are lower in the sur- face layer,and they are mostly in oxidized states, whereas C,O and N are enriched in the surface lay- er.The thickness of surface oxide layer is approximately 20 nm,this layer was assumed to be of great significance to various properties of amor- phous alloy Ni_(64)P_(20)Fe_(16),expecially to the chemical and catalytic properties.Experiments proved that transitional element Fe cannot improve oxidation resistance of the amorphous Ni-P system. 展开更多
关键词 amorphous alloy Ni_(64)P_(20)Fe_(16) surface layer composition chemical state
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Current spin polarization and spin injection efficiency in ZnO-based ferromagnetic semiconductor junctions
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作者 Gang JI Ze ZHANG +3 位作者 Yanxue CHEN Shishen YAN Yihua LIU Liangmo MEI 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2009年第2期153-160,共8页
[FeNi(3 nm)/Zn1-xCoxO(3 nm)]2/ZnO(d nm)/[Zn1-xCoxO(3 nm)/Co(3 nm)]2 (d=3 and 10) semiconductor junctions were prepared by magnetron sputtering system and photolithography. The spin valve effect was observe... [FeNi(3 nm)/Zn1-xCoxO(3 nm)]2/ZnO(d nm)/[Zn1-xCoxO(3 nm)/Co(3 nm)]2 (d=3 and 10) semiconductor junctions were prepared by magnetron sputtering system and photolithography. The spin valve effect was observed in these junctions because the utility of the ferromagnetic composite layers acted as soft and hard magnetic layers. The electrical detection was performed by measuring the magnetoresistance of these junctions to investigate the current spin polarization asc in the ZnO layer and the spin injection efficiency η of spin-polarized electrons. asc was reduced from 11.7% (and 10.5%) at 90 K to 7.31% (and 5.93%) at room temperature for d=3 (and d=10). And η was reduced from 39.5% (and 35.5%) at 90 K to 24.7% (and 20.0%) at room temperature for d=3 (and d=10). 展开更多
关键词 Spin injection Electrical detection MAGNETORESISTANCE Room temperature ferromagnetic semiconductor Ferromagnetic composite layers
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