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China Foundry 2014年第1期11卷 39-45页

作者： Wang Gaosong Zhao Zhihao Guo Qiang Cui Jianzhong key laboratory of electromagnetic Processing of materials Ministry of Education Northeastern University

The heat treatment process has great effects on microstructure and conductivity of ingots. In this study, the ingots of high strength 7075 aluminum alloy were prepared by low frequency electromagnetic casting(LFEC), and the effect of different homogenization processes(single-step homogenization at 465 ℃ for different holding times and three-step homogenization) on the microstructure and conductivity of 7075 aluminum alloy were studied by means of metallographic microscopy, electrical conductivity test, differential thermal analysis and X-ray diffraction phase analysis. For comparison, the ingot by conventional direct casting(DC) under the same conditions was also prepared. Results show that the non-equilibrium eutectic phases with low melting point in the ingot dissolve continuously into the matrix as the holding time of single-step homogenization increases. The endothermic peak of non-equilibrium phases can not be completely eliminated through a 24 h single-step homogenization, but can be eliminated after a three-step homogenization(200 ℃/2 h + 460 ℃/6 h + 480 ℃/12 h). Meanwhile, the homogenization has a better effect on the LFEC ingot than the conventional DC ingot. Under the same homogenizing conditions, the grains of LFEC ingot are characterized by a lower content of low melting point phases and the ingot shows higher electrical conductivity than DC ingot.

关键词： LFEC heat treatment 7075 aluminum alloy microstructure

Effect of Al_(82.8)Cu_(17)Fe_(0.2) alloy doping on structure and magnetic properties of SmCo5-based ribbons

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Journal of Rare Earths 2022年第1期40卷 93-101页

作者： Zhixin Dong Shu Wang Siyi Chen Yunfei Cao Zihui Ge Jibing Sun key Lab.for New Type of functional materials in Hebei province Hebei University of TechnologyTianjin 300401China

This work tries to improve the magnetic properties by multi-element doping in the form of a ternary ***_(5+)χwt%Al-Cu-Fe(x=0-7)ribbons melt-spun at 40 m/s were produced by adding Al_(82.8)Cu_(17)Fe_(0.2)alloy into SmCo_(5) matrix,and their phases,microstructure,and magnetic properties were *** results show that both x=0 and 3 ribbons form a cellular ***-Cu-Fe addition reduces the content of the Sm_(2)(Co,M)_(7) cell wall,narrows its width,and forms the local disordered micro-regions and solute-segregation nanoclusters in the Sm(Co,M)_(5) *** x increasing to5,Al-Cu-Fe addition promotes the phase separation between and within grains of the SmCo_(5)-based *** Al-Cu-Fe addition can simultaneously improve the coercivity and magnetization of the SmCo_(5)-based ribbons,in particular,the magnetization of the x=3 ribbons increases by 35%,while the coercivity of the x=5 ribbons increases by 3.9 ***,the microstructure evolution models are built up,and the relationship between the microstructure and the magnetic properties is discussed.

关键词： Rare earth alloys and compounds Rapid solidification Crystal structure Phase transitions microstructure Magnetic property

Au/Pt/InGaN/GaN Heterostructure Schottky Prototype Solar Cell

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Chinese Physics Letters 2009年第9期26卷 278-281页

作者：薛俊俊陈敦军刘斌谢自力江若琏张荣郑有炓 key laboratory of Advanced Photonic and Electronic materials Nanjing National Laboratory of Microstructure Department of Physics Nanjing University Nanjing 210093

A patterned Au/Pt/In0.2Ga0.8N/GaN heterostructure Sehottky prototype solar cell is fabricated. The forward current-voltage characteristics indicate that thermionie emission is a dominant current transport mechanism at the Pt/InGaN interface in our fabricated cell. The Sehottky solar cell has an open-circuit voltage of 0.91 V, short-circuit current density of 7mA/cm^2, and fill factor of 0.45 when illuminated by a Xe lamp with a power density of 300 mW/cm^2. It exhibits a higher short-circuit current density of 30 mA/cm^2 and an external quantum efficiency of over 25% when illuminated by a 20-roW-power He-Cd laser.

关键词： No English keyword

Effect of low frequency electromagnetic field on microstructures and macrosegregation of horizontal direct chill casting aluminum alloy

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中国有色金属学会会刊：英文版 2004年第6期14卷 1095-1099页

作者：赵志浩崔建忠董杰张海涛张北江 key laboratory of electromagnetic Processing of materials Ministry of Education Northeastern University Shenyang 110004 China

The influences of low frequency electromagnetic field on cast surface, microstructures and macrosegregation in horizontal direct chill(HDC) casting process were investigated experimentally. The cast surfaces, microstructures and macrosegregation of the ingots manufactured by conventional HDC and low frequency electromagnetic HDC casting were compared. The results show that low frequency electromagnetic field significantly improves the surface quality, refines the microstructures and reduces macrosegregation. Further more, increasing electromagnetic intensity or decreasing frequency is beneficial to the improvement. In the range of ampere-turns and frequency employed in the experiments, the optimum ampere-turns is found to be 10 000 A·turn and the frequency to be 30 Hz.

关键词：微观结构宏观偏析电磁场水平冷硬铸造

Microstructural evolution of high strength 7B04 ingot during homogenization treatment

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中国有色金属学会会刊：英文版 2008年第4期18卷 769-773页

作者：李念奎崔建忠 key laboratory of electromagnetic Processing of materials Ministry of Education Northeastern UniversityShenyang 110004China

The evolution of the microstructure and phases of the direct chill semicontinuous casting ingot of 7B04 super-high strength aluminum alloy during homogenization treatment was studied with metallographic analysis, scanning electron microscopy(SEM), energy spectroscopy and differential scanning calorimetry(DSC). The results show that a considerable amount of non-equilibrium eutectics containing Al, Zn, Cu and Mg exist in the direct chill semicontinuous casting ingot of 7B04 super-high strength aluminum alloy, and their melting point is 478 ℃. During homogenization treatment at 470 ℃, these eutectics dissolve into the matrix partly, coarsen and also transform into Al2CuMg phase whose equilibrium melting point is 490 ℃ in the alloy. Moreover, the homogenization treatment at 470 ℃ for 72 h results in the disappearance of the non-equilibrium eutectics though Al2CuMg phase can not dissolve completely.

关键词： 7B04铝合金微观结构低共熔性均匀化处理

Semi-solid Thixoforming Simulation of Al-Cu-Mn-Ti Alloy Parts via AnyCasting

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Journal of materials Science & Technology 2007年第3期23卷 359-362页

作者： Ping WANG Jianzhong CUI Guimin LU key laboratory of Ministry of Education for electromagnetic Processing of materials Northeastern University Shenyang 110004 China

The software AnyCasting was used to simulate the thixotropic die-casting process of semi-solid Al-Cu-Mn-Ti alloy slurry to form the parts of a particular shape, especially on how the in-gate size of die and injection speed affect the process. The results showed that the die cavity can be filled well with the semi-solid slurry in form of laminar flow under conditions that the temperature of the semi-solid slurry is 640℃ and that of die 200-240℃, thickness of in-gate is 11 mm and, more important, the injection speed should be changed from 0.1 to 1.0 m/s when 60% of die cavity has been filled. The simulation result is highly proved in conformity to the actual die-casting specimens in accordance to the filling process as simulated. Moreover, the hardness of the specimens is up to 116.6 HV after the treatment of solid solution plus underaging, i.e. 45.7% higher than that in conventional ones.

关键词： Al-Cu-Mn-Ti alloy Seml-solid die casting Laminar flow Hardness

A new high shear degassing technology and mechanism for 7032 alloy

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China Foundry 2015年第4期12卷 293-298页

作者： Yu-bo Zuo Yi-yao Kang Yue Lin Xu-dong Liu Chao Sun Sen-sen Yuan Jian-zhong Cui key laboratory of electromagnetic Processing of materials Ministry of Education Northeastern University

Degassing is very important for aluminum alloys especially for 7xxx series alloys. In the present study, a high shear technology was used to degas 7032 aluminum alloy in order to study its degassing efficiency. The experimental results showed that the high shear technology can significantly degas 7032 aluminum alloy. By applying intensive melt shearing and an Ar injection of 60 seconds, the density index, D,, was reduced from 13.25% to 0.28% and the hydrogen concentration was significantly i＇educed from 0.31 to 0.10 mL/100g AI. Compared with the conventional rotary degassing, high shear technology showed a much higher degassing efficiency, achieving a lower concentration of hydrogen in a shorter time. The water simulation experiment was used to study the mechanism of the high degassing efficiency. The small bubble size and the uniform distribution of Ar bubbles with the application of high shear technology are believed to be the main cause for the high degassing efficiency.

关键词： aluminum alloy hydrogen degassing intensive melt shearing porosity water simulation

Magnetic stimulation at Neiguan(PC6) acupoint increases connections between cerebral cortex regions

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Neural Regeneration Research 2016年第7期11卷 1141-1146页

作者： Hong-li Yu Gui-zhi Xu Lei Guo Ling-di Fu Shuo Yang Shuo Shi Hua Lv province-Ministry Joint key laboratory of electromagnetic Field and Electrical Apparatus Reliability Hebei University of Technology

Stimulation at specific acupoints can activate cortical regions in human *** studies have mainly focused on a single brain ***,the brain is a network and many brain regions participate in the same *** study of a single brain region alone cannot clearly explain any brain-related ***,for the present study,magnetic stimulation was used to stimulate the Neiguan（PC6） acupoint,and 32-channel electroencephalography data were recorded before and after *** functional networks were constructed based on electroencephalography data to determine the relationship between magnetic stimulation at the PC6 acupoint and cortical *** indicated that magnetic stimulation at the PC6 acupoint increased connections between cerebral cortex regions.

关键词： stimulation acupoint cortex cortical participate frontal minutes alone handed acupuncture

Structural Design Strategies of Polymer Matrix Composites for electromagnetic Interference Shielding:A Review

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Nano-Micro Letters 2021年第11期13卷 322-350页

作者： Chaobo Liang Zhoujie Gu Yali Zhang Zhonglei Ma Hua Qiu Junwei Gu key laboratory of functional Nanocomposites of shanxi province College of Materials Science and EngineeringNorth University of ChinaTaiyuan 030051China Shaanxi key laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXian 710072China Research and Development Center Guangdong Suqun New Materials Co.LtdDongguan 523000China

With the widespread application of electronic communication technology,the resulting electromagnetic radiation pollution has been significantly *** matrix electromagnetic interference(EMI)shielding materials have disadvantages such as high density,easy corrosion,difficult processing and high price,*** matrix EMI shielding composites possess light weight,corrosion resistance and easy ***,the current polymer matrix composites present relatively low electrical conductivity and poor EMI shielding *** review firstly discusses the key concept,loss mechanism and test method of EMI *** the current development status of EMI shielding materials is summarized,and the research progress of polymer matrix EMI shielding composites with different structures is illustrated,especially for their preparation methods and ***,the corresponding key scientific and technical problems are proposed,and their development trend is also prospected.

关键词： Polymer matrix composites electromagnetic interference shielding Structural design

Nucleation and three-dimensional morphology of intragranular ferrite in a vanadium microalloyed steel

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Journal of University of Science and Technology Beijing 2005年第4期12卷 326-328页

作者： Kaiming Wu Xinlai He materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China Lab of Three-dimensional Analysis and Characterization of materials microstructure Hubei province key laboratory for Refractory and Ceramics-Ministry-province Jointly-constructed Cultivation Base for State key laboratory Wuhan University of Science and Technology Wuhan 430081 China

The formation of intragranular ferrite at inclusions was analyzed by SEM-EDX in a vanadium microalloyed steel with an excess amount of sulfur. The precipitation of MnS at aluminum oxides may result in Mn depletion, which, in turn, promotes the formation of intragranular ferrite. The morphology of intragranular ferrite changed with undercooling. At higher temperatures intragranular ferrite is nearly equiaxed whereas it is plate-like at lower temperatures.

关键词： microalloyed steels intragranular ferfite nucleation three-dimensional morphology