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Manufacturing Technology 2015年第4期15卷 4-4页

作者： Bakalova, Totka Louda, Petr Voleský, Lukáš Borůvková, Karolína Svobodová, Lucie Institute for Nanomaterials Advanced Technologies and Innovation Technical University of Liberec Studentská 2 Liberec461 17 Czech Republic Faculty of Mechanical Engineering Department of Material Science Technical University of Liberec Studentská 2 Liberec461 17 Czech Republic

Productivity growth in the machining industry is associated with a reduction in the cost of cleaning and recycling contaminated process fluids. The proper use of process fluids or lubricants can bring a significant reduction in friction and the amount of wear, thereby leading to a reduction in power consumption. The use of nanolubricants in modern technologies is a major advancement. Nanolubricant is a new system composed of nanometer-sized particles dispersed in a base lubricant. The use of nanoadditives in the form of nanoparticles is highly efficient due to their high chemical and biological activity. The doping of lubricants with nanoparticles is one of the ways to solve problems with the removal of bacteria, whereby improving the biological, chemical and technological stability of process fluids. In the article, we monitor the effects of doping process fluids with nanoparticles of silica (SiO2) and titanium dioxide (TiO2) on the friction coefficient of friction pairs of Si3N4 balls against steel 16MnCr5, EN 10084-94 and Si3N4 balls against aluminium AlCu4BiPb balls. © 2015. Published by Manufacturing Technology. All rights reserved.

关键词： Tribology

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Effect of fullerene-C60&C70 on the microstructure and properties of 96.5Sn-3Ag-0.5Cu solder

Effect of fullerene-C60&C70 on the microstructure and proper...

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Electronic Components and Technology Conference (ECTC)

作者： Guang Chen Fengshun Wu Changqing Liu Y.C. Chan State Key Laboratory of Material Processing and Die & Mould Technology Huazhong University of Science and Technology Wuhan China Wolfson School of Mechanical and Manufacturing Engineering Loughborough University Loughborough UK Department of Electronic Engineering City University of Hong Kong KowLoon Tong Hong Kong

In this study, fullerene nanoparticles (FNSs, a mixture of approximately 80%C60, 20%C70), by varying their weight fractions (0.05, 0.1 and 0.2wt. %) were successfully added into the SAC305 lead free solder to fabricate composite solders through the powder metallurgy processing route. As well as the retained ratios of fullerene reinforcements in the solder joints were firstly tested, the composite solders were also characterized in terms of their microstructure, melting points, electrical conductivity, wettability and mechanical properties. The retained ratio of FNSs reinforcements in the solder joints shows a considerable decrease with the increase of reflow cycles. After FNSs addition to the solder alloy, the Sn rich phase and IMC phases (Cu 6 Sn 5 and Ag 3 Sn) with a finer microstructure were observed in the solder matrix. With the increasing addition of fullerene, the composite solders showed an improvement in their wetting property but an insignificant change in their melting points and conductivity. The mechanical results indicated that the addition of 0.2wt. % fullerene can lead to 12.1% and 28.2% improvement in micro-hardness and shear strength respectively, when compared with that of the unreinforced solders. Furthermore, the FNSs doped composites exhibited better mechanical performance throughout the 360h aging period. These results obtained from this study proved that the addition of fullerene can improve not only the mechanical properties of the solder alloy, but also the wettability without any notable effect on the melting point and conductivity. Thus, these fullerene doped composite solders can be further developed as a potential material for microelectronics assembly and packaging industry.

关键词： Nanoparticles Soldering Metals Aging Resistance Microstructure Temperature measurement

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Enhanced mechanical properties of a 0.22c-Mn-Si-Cr low alloyed steel treated by ART and Q&P processes

Enhanced mechanical properties of a 0.22c-Mn-Si-Cr low alloy...

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4th International Conference on Advanced engineering materials and Technology, AEMT 2014

作者： An, Bai Feng Gao, Gu Hui Gui, Xiao Lu Tan, Zhun Li Bai, Bing Zhe Department of Mechanical and Electronic Control Engineering Beijing jiaotong University China School of material science and engineering Tsinghua University China

ISBN: (纸本)9783038352068

There is a currently desirable demand for high strength steels with good ductility reduce the weight of steel parts for automobile and train applications. Retained austenite in steels can improve the toughness and plasticity. The austenite reverse transformation + quenching and partitioning (ART + Q&P) process was treated on a 0.2C-Mn-Si-Cr low alloyed steel, a multiphase microstructure composed of intercritical ferrite (IF), martensite, bainite and retained austenite (RA) can be obtained in the low carbon steel. Microstructures of the steel treated by different heat treatments were characterized by SEM and XRD. Results show that the formation of RA in low alloy steel depends on the following: (1) the enrichment of the carbon and manganese in the reversed austenite during the ART step;(2) the secondary enrichment of carbon in retained austenite during the following Q&P step. High fraction of RA (14 vol.%) was obtained through the two-step element enrichment treatment (ART + Q&P). Due to continuous TRIP effect of RA during the deformation, a good combination of strength and plasticity was achieved in our works: the product of strength and elongation is greater than 35 GPa•%, the tensile strength is more than 1230 MPa, the yield strength greater than 890 MPa, the total elongation is about 28.6%. © (2014) Trans Tech Publications, Switzerland.

关键词： Bainite

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Growth mechanism of Co:TiO2 thin film deposited by metal organic chemical vapor deposition technique

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IOP Conference Series: materials science and engineering 2016年第1期128卷

作者： A Saripudin P Arifin Study Program of Electrical Engineering Dept. of Electrical Engineering Education Faculty of Technology and Vocational Universitas Pendidikan Indonesia Jl. Dr. Setiabudi 207 Bandung 40154 West Java Indonesia Physics of Electronics Material Lab. Study Program of Physics Faculty of Mathematics and Natural Science Institut Teknologi Bandung Jl. Ganeca 10 Bandung 40132 West Java Indonesia

In this research, we investigated the growth mechanism of cobalt-doped titanium dioxide (Co:TiO2) films. Thi Co:TiO2 thin films were grown on the n-type silicon substrate. The films were grown by metal organic chemical vapor deposition method. The growth temperature was varied of 325°C – 450°C. The films were characterized by SEM. Using Arheniu's equation, it is known that the activation energy value of film growth is positive in the range of temperature of 325°C – 400°C and negative in the range of temperature of 400°C – 450°C. These results show that the decomposition rate in the range of temperature of 325°C – 400°C is due to diffusion phase of precursor gas. On the other hand, the decomposition rate decreased in the range of temperature of 400°C – 450°C because the precursor gas decreased, and the surface chemical reaction was high.

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Evolutions of nonlinear acoustics and microstructural change during creep in Gr. 122 steel welded joint

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Zairyo/Journal of the Society of materials science, Japan 2015年第2期64卷 80-87页

作者： Ohtani, Toshihiro Honma, Takumi Ishii, Yutaka Tabuchi, Masaaki Hongo, Hiromichi Hirao, Masahiko Dept. Mechanical Engineering Shonan Inst. of Tech. Tsujido-Nishikaigan Fujisawa 251-8511 Japan Shona Inst. of Tech. Tsujido-Nishikaigan Fujisawa 251-8511 Japan National Institute for Material Science Sengen Tsukuba305-0047 Japan Graduate School of Engineering Science Osaka University Machikaneyama Toyonaka 560-8531 Japan

ASME Grade 122 (11Cr-0.4Mo-2W-CuVNb) has been used for boiler components in ultra-supercritical (USC) thermal power plants at approximately 873 K. The creep life of the welded joints in this steel decreased as a result of Type IV creep damage that forms in the heat-affected zone (HAZ) under long-term use at high temperatures. In this study, we investigated the relationship between microstructural change and the evolutions of two nonlinear acoustic characterizations with electromagnetic acoustic resonance (EMAR) throughout the creep life in the welded joints and the correlation between two nonlinear acoustic characterizations. One was resonant frequency shift and other three-wave mixing. EMAR was a combination of the resonant acoustic technique with a non-contact electromagnetic acoustic transducer (EMAT). We used bulk wave EMAT, which transmits and receives shear wave propagating in thickness direction of a plate specimen. Creep tests of thick welded joints specimens were interrupted at several time steps at 873 K, and 90 MPa. Two nonlinear acoustic parameters and ultrasonic attenuation decreased from the start to 50% of creep life. After slightly increased, they rapidly increased from 80% of creep life to rupture. We interpreted these phenomena in terms of dislocation recovery, recrystallization, and restructuring related to the initiation and growth of creep void, with support from the SEM and TEM observation. This noncontact resonance-EMAT measurement can monitor the evolution of nonlinear acoustics throughout the creep life and has a potential to assess the Type IV creep damage advance and to predict the creep life of high Cr ferritic heat resisting steels. ©2015 The Society of materials science, Japan.

关键词： Creep

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Microstructure and mechanical Properties of Ductile Cast Iron in Lost Foam Casting with Vibration

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Journal of Iron and Steel Research International 2014年第11期21卷 1049-1054页

作者： Bo-tao XIAO Zi-tian FAN Wen-ming JIANG Xin-wang LIU Wei LONG Qiang HU State Key Laboratory of Material Processing and Die & Mould Technology Huazhong University of Science and Technology School of Materials Science and Engineering Jiangxi Science and Technology Normal University School of Mechanical & Electrical Engineering Wuhan Institute of Technology Jiangxi Key Laboratory for Advanced Copper and Tungsten Materials Jiangxi Academy of Sciences

The microstructures and mechanical properties of the ductile cast iron （DI） specimens obtained by lost foam casting （LFC） with and without vibration were investigated. The results indicate that the number of the graphite nodule increases from 175 mm 2 of the specimens produced by LFC without vibration to 334 mm^-2 of the specimens produced by LFC with vibration, and the thickness of the ferrite shell increases. Meanwhile, the amount of the carbides decreases in the specimens produced by LFC with vibration and the granule structure then forms. These are mainly attributed to the ＂crystal shower＂ caused by the vibration. In addition, the tensile strength and elongation of DI specimens produced by LFC with vibration are improved due to the dispersion-strengthening of refined carbide and Dearlite colonv, uniform distribution of the graphite nodule, and increase of the amount of dimples and tearing edges.

关键词： ductile cast iron （DI） microstructure mechanical property mechanical vibration lost foam casting （LFC）

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Structural design of assisted washing-hand device for a one-armed man using TRIZ theory

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Key engineering materials 2014年 621卷 675-680页

作者： Jiang, Jingang Tang, Zexu Li, Pengjie Xu, Wenhua Wang, Xuefei Li, Jiantao Liu, Yunfeng Intelligent Machine Institute Harbin University of Science and Technology China School of Mechanical and Power Engineering Harbin University of Science and Technology China Heilongjiang College of Education China School of Material Science and Engineering Harbin University of Science and Technology China School of Management Harbin University of Science and Technology China

ISBN: (纸本)9783038351863

Aiming to the difficulty of washing-hand for a one-armed man, functional requirements of washing-hand for a one-armed man is analyzed, and TRIZ theory is described in detail. A novel conceptual assisted washing-hand device for a one-armed man is put forward in this paper. Innovative problems of the assisted washing-hand device design were solved based on contradiction conflict matrix theory and material field theory of TRIZ. The whole three-dimensional model of assisted washing-hand device is built. TRIZ theory can provide the reference basis for structural design of assisted washing-hand device for a one-armed man. © (2014) Trans Tech Publications, Switzerland.

关键词： Washing

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Gating system optimization of low pressure casting A356 aluminum alloy intake manifold based on numerical simulation

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China Foundry 2014年第2期11卷 119-124页

作者： Jiang Wenming Fan Zitian School of Mechanical&Electrical Engineering Wuhan Institute of Technology State Key Laboratory of Material Processing and Die&Mould Technology Huazhong University of Science and Technology

To eliminate the shrinkage porosity in low pressure casting of an A356 aluminum alloy intake manifold casting, numerical simulation on fi lling and solidifi cation processes of the casting was carried out using the ProCAST software. The gating system of the casting is optimized according to the simulation results. Results show that when the gating system consists of only one sprue, the fi lling of the molten metal is not stable; and the casting does not follow the sequence solidifi cation, and many shrinkage porosities are observed through the casting. After the gating system is improved by adding one runner and two in-gates, the fi lling time is prolonged from 4.0 s to 4.5 s, the fi lling of molten metal becomes stable, but this casting does not follow the sequence solidifi cation either. Some shrinkage porosity is also observed in the hot spots of the casting. When the gating system was further improved by adding risers and chill to the hot spots of the casting, the shrinkage porosity defects were eliminated completely. Finally, by using the optimized gating system the A356 aluminum alloy intake manifold casting with integrated shape and smooth surface as well as dense microstructure was successfully produced.

关键词： low pressure casting A356 aluminum alloy numerical simulation optimization intake manifold

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A New Method of Robust Phosphor Glass Fabrication and Performances for LEDs Fabrication of Thermal Stability Phosphor Glass and Performances

A New Method of Robust Phosphor Glass Fabrication and Perfor...

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International Conference on Electronic Packaging Technology

作者： Liang Yang An Xie Dan Xie Xiayun Shu School of Material science and Engineering Xiamen University of Technology Xiamen China School of Mechanical science and Engineering Xiamen University of Technology Xiamen China

ISBN: (纸本)9781467380003

In this paper, a simple and practical method for preparing phosphor glass is proposed. Phosphor distribution and element analysis are investigated by optical microscope and FESEM. The phosphor particles dispersed in matrix is vividly observed and their distributions are uniform. Spectrum distribution and color coordinates depended on thickness of screen printed phosphor layer coupled with blue LED chip are studied. TG analysis shows phosphor glass shows excellent thermal stability in comparison to phosphor silicon. This study opens up many possibilities for applications using the phosphor glass on a selected chip which emission is well absorbed by all phosphors. The screen printing technique also offers possibilities for the design and engineering of complex phosphor layers on glass substrates. Phosphor screen printing technology allows the realization of high stability and thermal conductivity for phosphor layer. And this simple phosphor glass method provides many possibilities for LED packing, including TFFC (thin film flip chip) and remote phosphor technology.

关键词： YAG Phosphor glass LED

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Wear resistance of ion implanting tungsten carbide on 65mn steel used as harrow disk 2

Wear resistance of ion implanting tungsten carbide on 65mn s...

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2nd International Conference on materials, Transportation and Environmental engineering, CMTEE 2014

作者： Yang, Hai Jiao, Ren Bao Wang, Shu Yang Northeast Forestry University College of mechanical and electrical engineering Harbin China Jiamusi University College of Material Science and Engineering Jiamusi China

ISBN: (纸本)9783038352488

To improve the harrow disk made of 65Mn steel working life, an ion implanting metal in order to obtain tungsten carbide treatment was proposed in this work. Microstructure and phase composition of 65Mn steel obtained by ion implanting tungsten carbide process were analyzed by optical microscope and XRD, respectively. The surface hardness was tested by microscopic hardness tester, and the wear resistant performance of the wear layer was tested by abrader abrasor. The results showed that the micro-hardness of ion implanting tungsten carbide layer can be reached 1100 HV0.2, higher than that of 65Mn steel, the thickness of tungsten carbide layer was 400μm, which greatly improve the wear resistance. Harrow disk after the ion implanting tungsten carbide exhibited the excellent wear resistance in the sandy soil, and its working life was more than twice the length of the genera treatment harrow disk. © (2014) Trans Tech Publications, Switzerland.

关键词： Ions

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