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Preparation of ultra-fine Aluminum Nitride in Thermal Plasma

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Plasma Science and Technology 2002年第4期4卷 1417-1420页

作者：漆继红罗义文印永祥代晓雁 School of Chemical Engineering of Sichuan University Chengdu 610065 China

ultra-fine aluminum nitride has been synthesized by the evaporation of aluminum powder at atmospheric-pressure nitrogen plasma in a hot-wall reactor. The average size of aluminum nitride particle is 0.11 μm measured by scanning electric mirror (SEM), and the purity is at least over 90% evaluated by X-Ray diffraction (XRD). The conversion of Al powder to aluminum nitride is strongly depended on the injection of NH3. Typical experimental parameters such as the feed rate of raw material, the flow rate of ammonia and the position of injecting aluminum powder into the reactor are given.

关键词： thermal plasma ultra-fine aluminum nitride

Manufacturing of High-efficiency Air Filter Paper Using ultra-fine Fibers

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Paper And Biomaterials 2019年第1期4卷 17-22页

作者： Yong-Chil Ro Yong-Il Ri Guang-Jin Jong Institute of Paper Engineering State Academy of Sciences

In this paper,the manufacturing of high-efficiency air filter paper is *** air filter paper was produced using ultra-fine fibers and wateroat fibers mercerized by alkali,using an electrospinning apparatus with multiple *** high efficiency air filter paper has an antibacterial effect after adding a chitosan-copper complex which is harmless to *** a result of the measurement,the filtering efficiency of the air filter paper is approximately 99.998%and its antibacterial efficiency is approximately 99.5%.

关键词： ultra-fine fiber wateroat(Zizania latifolia)fiber chitosan-copper complex air filter paper

Flow Properties of ultra-fine Bubble Mixtures Passing through Micro-Apertures

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Journal of Flow Control, Measurement & Visualization 2015年第3期3卷 111-121页

作者： Akiomi Ushida Tomiichi Hasegawa Takatsune Narumi Itaru Kourakata Yoshinori Nakamoto Faculty of Engineering Niigata University Niigata-shi Japan Niigata College of Technology Niigata-shi Japan Institute for Research Collaboration and Promotion Niigata University Niigata-shi Japan TECH CORPORATION Co. Ltd. Hiroshima-shi Japan

The flow properties of fine bubble mixture flows are investigated and reported. Few previous studies have focused on ultra-fine bubble (UFB) mixtures, which contain sub-micrometer sized bubbles. In this study, UFB mixtures of water and glycerol solution are passed through micro-sized slits and capillaries, and the resultant pressure drops are evaluated in comparison with those for water and aqueous glycerol alone. The experimentally measured pressure drop for slits (≤51 μm) and capillaries (≤81 μm) is less for UFB mixtures than for water and aqueous glycerol alone. This phenomenon is considered in terms of interface behavior and attributed to the electric interaction between an electric double layer and the UFBs. Furthermore, numerical observation for slip wall conditions is conducted, and the results for UFB mixtures agree with the predicted values for slip wall conditions.

关键词： Micro-Aperture ultra-fine Bubble Water Glycerol Pressure Drop

Study on ultra-fine Microstructure of Cast Iron under Rapid Solidification

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Journal of Harbin Institute of Technology(New Series) 1999年第1期6卷 5-7页

作者：郭景杰李邦盛李培杰贾均李庆春李言祥

The ultra-fine microstructrue of cast iron has been studied under rapid solidification by laser rapid meltingand solidifying method and SEM and TEM technology and results show cementite, martensite, austenite and ultra-fineperlite phases can be obtained under rapid solidification and many dislocations have been the found in cementite.

关键词： Cast iron laser rapid solidification ultra-fine miicrostructure dislocation

Groove Design and Microstructure Research of ultra-fine Grain Bar Rolling

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Modeling and Numerical Simulation of Material Science 2012年第4期2卷 67-75页

作者： Xuetong Li Lei Cao Minting Wang Fengshan Du College of Mechanical Engineering National Engineering Research Center for Equipment and Technology of Cold Rolling Strip Yanshan University Qinhuangdao China

New flat-oval groove rolling process of multi-direction deformation is proposed to manufacture ultra-fine grain bar. Application of new groove series can introduce uniform large plastic strain into whole cross section of the material, and meanwhile satisfy the requirements of shape and size. Principle of grain refinement, based on experimental research of small specimen, is that grain refinement of ferrite is mainly dynamic recrystallization when low-carbon alloy steel is at low temperature deformation. Relationship of grain size and z-factor is also obtained through experimental research, as well as ultra-fine ferrite grain less than 1 micron. To predict strain, shape, dimensions and grain size of the material in rolling process, numerical simulation model of the warm groove bar rolling process is established via nonlinear finite element method, and distribution of grain size of the final section is obtained via finite element subroutine. The result indicates that ultra-fine grain bar rolling can accomplish at low temperature region.

关键词： Bar FEM Flat-Oval Groove Large Plastic Strain Low Temperature ultra-fine Grain

Effect of thermal annealing on the microstructure, mechanical properties and residual stress relaxation of pure titanium after deep rolling treatment

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Journal of Materials Science & Technology 2019年第3期35卷 409-417页

作者： Jie Huang Kai-Ming Zhang Yun-Fei Jia Cheng-Cheng Zhang Xian-Cheng Zhang Xian-Feng Ma Shan-Tung Tu Key Laboratory of Pressure Systems and Safety Ministry of Education School of Mechanical and Power Engineering East China University of Science and Technology AECC Commercial Aircraft Engine Co. Ltd. Shanghai Engineering Research Center for Commercial Aircraft Engine Sino-French Institute of Nuclear Engineering and Technology SunYat-Sen University

The aim of this paper was to investigate the effect of thermal annealing on the microstructure, mechanical properties, and residual stress relaxation of deep rolled pure titanium. The microstructure and mechanical properties of the surface modified layer were analyzed by metallographic microscopy, transmission electron microscope and in-situ tensile testing. The results showed that the annealed near-surface layer with fine recrystallized grains had increased ductility but decreased strength after annealing below the recrystallization temperature, where the tensile strength was still higher than that of the substrate. After annealing at the recrystallization temperature, the recrystallized near-surface layer had smaller grain size,similar tensile strength, and higher proportional limit, comparable to those of the substrate. Moreover, the residual stress relaxation showed evidently different mechanisms at three different temperature regions:low temperature(T≤ 0.2 Tm), medium temperature(T≈(0.2–0.3) Tm), and high temperature(T≥ 0.3 Tm).Furthermore, a prediction model was proposed in terms of modification of Zener-Wert-Avrami model,which showed promise in characterizing the residual stress relaxation in commercial pure Ti during deep rolling at elevated temperature.

关键词： Deep rolling ultra-fine grain Tensile strength Microstructure Residual stress

Crystal Structure of BaxSr1-xTiO3fine Powder

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Journal of Modern Physics 2015年第1期6卷 70-77页

作者： Natheer B. Mahmood Emad K. Al-Shakarchi Brahim Elouadi Xavier Feaugas Physics Department College of Science Al-Nahrain University Baghdad Iraq Laboratoire des Sciences de l’Ingénieur pour l’Environnement Université de La Rochelle La Rochelle France

Various compositions of the system BaxSr1-xTiO3 (BST) have been elaborated both as fine powders and ceramic monoliths, using the co-precipitation route within a warmed supersaturated solution of oxalic acid. The appropriate stoichiometry was determined from the mixtures of precisely titrated aqueous solutions of cations chlorides (SrCl2, BaCl2, and TiCl4). The reason of this process was to apply low sintering temperature in production of BST samples with ultra-fine powders. These powders primarily calcined at (850°C) for (5 hr) were used to elaborate ceramics after pellets sintering at (1200°C) during (8 hrs). Indeed, XRD patterns were confirmed that the samples are a pure phase and a perovskite cubic structural type at (x = 0, 0.5, 0.6). Whereas, (x = 0.7, 0.8, 0.9, 1) showed a tetragonal phase. There is agreement between the FTIR and XRD analysis, by the relation of the wave vector (K) and lattice constant. It was deduced a stimulated relation between (x) and (K). The results of TEM, they were clear that the lowest particle sizes investigated of BST powders nearly (36 - 50 nm).

关键词： Barium Strontium Titanate Oxalate Co-Precipitation Method X-Ray Diffraction Transmission Electron Microscope ultra-fine Powder

样品粒度对封闭酸溶-ICP-MS分析性能的影响

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质谱学报 2005年第Z1期26卷 21-22页

作者：孙德忠何红蓼国家地质实验测试中心北京100037 国家地质实验测试中心北京100037

To improve precision of analytical results of pressurized acid digestion-ICP-MS, the first step is to improve the homogeneity by reducing the particle size of sample. Using of ultra-fine sample (-500 mesh) can reduce ... 详细信息

关键词： pressurized acid digestion inductively plasma mass spectrometry(ICP-MS) ultra-fine sample

封闭酸溶-ICP-MS分析超细地质样品的条件优化

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质谱学报 2005年第Z1期26卷 23-24,72页

作者：何红蓼孙德忠国家地质实验测试中心北京100037 国家地质实验测试中心北京100037

Using ultra-fine sample for determination 42 elements by pressurized acid digestion -ICP-MS, the mass of test portion can be reduced to 2 mg yet maintain the representation. And acid used for digestion could be reduce... 详细信息

关键词： inductively plasma mass spectrometry (ICP-MS) ultra-fine sample pressurized acid digestion