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Numerical Simulation of the TIG welding Arc Behavior

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Journal of Materials Science & Technology 2002年第1期18卷 43-46页

作者： Chuansong WU and Jinqiang GAOInstitute of Materials Joining, Shandong University, Jinan 250061, China [ Manuscript received January 2, 2001, in revised form February 14, 2001] Inst. of Mat. Joining Shandong Univ. Jinan 250061 China

Achieving an effective utilization and exploitation of TIG welding arcs require a thorough understanding of the plasma properties and its physical processes. Through simultaneous solutions of the set of conservation equations for mass, momentum, energy and current, a mathematical model has been developed to predict the velocity, temperature, and current density distributions in argon welding arcs. The predicted temperature fields in arc regions, and the distribution of current density and heat flux at the anode agree well with measurements reported in literatures. This work could lay the foundation for developing a comprehensive model of the TIG welding process where a dynamic, two-way coupling between the welding arc and the weld pool surface is properly represented.

关键词： welding Argon arc Plasma Behavior

Electron beam welding of Re and BT5-1 titanium alloy

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Rare Metals 2005年第3期24卷 293-297页

作者： YANG Shanglei XUE Xiaohuai LOU Songnian CHEN Yan LI Shimin Institute of welding Shanghai Jiaotong University Shanghai 200030 China

Based on the binary alloy phase diagram of Re-Ti, the weldability of Re and BT5-1 titanium alloy was analyzed. Using two methods of direct electron beam welding （EBW-D） and intergradafion electron beam welding （EBW-I）, Re and BT5-1 was welded. Experimental results show that the joint figuration of EBW-D between Re and BT5-1 is not fine, and the joint is inclined to brittleness rupture. The joint figuration of EBW-I between Re and BT5-1 is fine. No cracking and other disfigures occur in the intergradation joint. The element distribution of Re, Me, and Ti in the weld metal is progressional diversification.

关键词： welding intergradation layer electron beam rhenim titanim alloy

Current Density-Sensitive welding of a Semiconductor Nanowire to a Metal Electrode

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Chinese Physics Letters 2013年第1期30卷 199-203页

作者：谭玉王岩国 Science College Hunan Agricultural UniversityChangsha 410128 Beijing Laboratory of Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesP.O.Box 603Beijing 100190

In situ welding of a single ZnSe nanowire(NW)to an Au electrode has been successfully achieved by means of current-induced Joule heating.The parameter governing the welding of semiconductor NW to the metal electrode is highly dominated by the current density at the Au-ZnSe NW(M-S)contact because current density at the M-S contact can change the temperature profile along the NW.The self-heating behaviors of the Au-ZnSe NW-Au(M-S-M)nanostructure can be changed from the electrical failure of the ZnSe NW to the melting of the Au electrode localized at the M-S contact when the current density at the M-S junction was adjusted to be larger than in the NW.Consequently,the self-welding is the current density-sensitive and controllable since the current density at the M-S contact can be controlled by adjusting the contact area between the NW and metal electrode.This controlled self-welding may have potential applications in the construction of a complex nanostructure and improvement of the thermal stability of the M-S contact as well as the enhanced performance of the nanodevices based on the M-S-M nanostructure.

关键词： welding electrode contact

Kinetic Model of TiN Particle Dissolution and Coarsening during welding Thermal Cycle

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Journal of Materials Science & Technology 2002年第5期18卷 439-442页

作者： Mao'aiCHEN ChuansongWU JinqiangGAO YiminTANG Lab. of Liquid Structure Shandong Univ. Ji'nan 250061 China Inst. of Mat. Joining Shandong Univ. Ji'nan 250061 China Sch. of Mat. Sci. and Eng. Shanghai Jiaotong Univ. Shanghai 200030 China

With carbon extraction replica technique, electron diffraction and EDAX analysis, second particle size distribution in two Ti microalloyed steels and their heat-affected zones were investigated. The results show that the particles in the Ti microalloyed steels are TiN particles, and the TiN particles in the steel with lower Ti/N ratio exhibit smaller size and lower dissolution and coarsening rate and extent. Based on the investigation results, kinetic models for TiN particle dissolution and coarsening during welding thermal cycle were developed. The predicted values calculated by using the models are in good agreement with the experimental ones.

关键词： TiN particle welding Dissolution Coarsening

Prediction Models on Distribution of Inherent Strains in T Type welding Structure

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Journal of Materials Science & Technology 2003年第Z1期19卷 202-204页

作者： Peng HE Jicai FENG Jiecai HAN Yiyu QIAN National Key Laboratory of Advanced welding Production Technology HIT Harbin 150001 China National Key Laboratory of Advanced Welding Production Technology HIT Harbin 150001 China National Key Laboratory of Advanced Welding Production Technology HIT Harbin 150001 China National Key Laboratory of Advanced Welding Production Technology HIT Harbin 150001 China

A fundamental theory for the analysis of residual welding stresses and deformation based on the inherent strain distribution along the welded joint is introduced. The method of predicting maximum hardness Hv(y, z) and maximum inherent strain gmax is given. The model T.E.P-Tav-hardness calculation is proposed to predict distribution of inherent strains in T type welding structure. By T.E.P-Tav-hardness calculation, distribution of longitudinal inherent strains can be predicted in T type welding structure, and calculation and experimental results are consistent.

关键词： Inherent strain, Residual welding stresses, T type welding

50 Years Experience of the E.O.Paton Electric welding Institute in Field of Electron Beam welding

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稀有金属材料与工程 2011年第S4期40卷 6-13页

作者： O.K.Nazarenko V.M.Nesterenkov E.O.Paton Electric welding Institute of the NAS of Ukraine

Studying the possibilities of electron beam welding (EBW) and the principles of construction of equipment for electron beam welding,led by academician Boris Evgenyevich Paton,began at the E.O.Paton Electric welding Institute (PWI) in 1958.It resulted in development of the first laboratory-scale plant and welding of different small workpieces.One year later the method of electron beam welding turned out to be in great demand:in nuclear power engineering,in production of electric vacuum devices and liquid-fuel rocket engines.In 1961-1962 owing to effective coordination of work performed at government level,the first production machines for electron beam welding were put into operation at a number of branch enterprises.Within the next few years,application of electron beam welding became wider,first of all in the above mentioned industries,and simultaneously electron beam welding began to be accepted by aircraft and power engineering industry.In 1960-s PWI organized in Ukraine full-scale production of power units,developed by it (guns,power sources and control systems) on the basis of Sumy Factory of Electron Microscopes.72 complete sets of power source units of SP-30 type (25 kV,500 mА),330 complete sets of U-250А (30 kV,450 mА),320 complete sets of ELA-60 (60 kV,250,500 and 1000 mА) and ELA-120 (120 kV,1000 mА) were manufactured in different periods of time.On October 16th 1969 the first test of electron beam welding and cutting of metals was carried out in ?Soyuz-6? spaceship,that practically initiated the space technology.Testing was performed in Vulkan unit developed by PWI.Considering that in space X-radiation and difficulties with high-voltage insulation could eliminate the possibility of electron beam application,low accelerating voltage (not higher than 8 kV) was used.

关键词： electron beam welding Paton Electric welding Institute technology equipment material engineering

Indirect Measurement of Material Thermal and Mechanical Properties during welding

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Journal of Materials Science & Technology 2003年第Z1期19卷 173-175页

作者： Dongqing LI Jun TAO Qingguo Meng Hongyuan FANG State Key Laboratory of welding Harbin Institute of Technology 150001 Chins State Key Laboratory of Welding Harbin Institute of Technology 150001 Chins State Key Laboratory of Welding Harbin Institute of Technology 150001 Chins State Key Laboratory of Welding Harbin Institute of Technology 150001 Chins

By means of a newly developed non-contact detecting method, electronic speckle pattern interferometry (ESPI), a method of determining material property data during welding is studied. A TIG fixed-point welding process is modeled in which some achievements of simulation, such as the effect of welding pool on temperature field and nonlinear relation between convection coefficient and temperature, are all considered. In addition, by taking into account effect of heating rate, the workpiece is divided into near-weld zone and far-weld zone, which will be treated with different property values. When the displacement field computed with original property data is compared and matched with the experimental displacement field, which is measured by ESPI, these original data are adjusted properly. A group of raw properties are obtained and are corrected by statistical regression before they enter the simulation process again.By such a loop of "simulation-comparison-modification", a set of property data that best satisfy the real condition are achieved finally. In such a way, a new method for measuring material properties during welding is found.

关键词： Material properties, welding displacement field, Numerical simulation, ESPI

Influence of tool plunge depth and welding distance on friction stir lap welding of AA5454-O aluminum alloy plates with different thicknesses

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中国有色金属学会会刊：英文版 2012年第S3期22卷 624-628页

作者： Jun-Won KWON Myoung-Soo KANG Sung-Ook YOON Yong-Jai KWON Sung-Tae HONG Dae-Il KIM Kwang-Hak LEE Jong-Dock SEO Jin-Soo MOON Kyung-Sik HAN School of Materials Science and Engineering University of Ulsan School of Mechanical Engineering University of Ulsan Technical Research Laboratories Shin Young Co.Ltd. Automotive Parts Innovation Center Ulsan Technopark

AA5454-O aluminum alloy plates with thicknesses of 1.4 and 1.0 mm were friction-stir-lap-welded (FSLWed).The influences of the tool plunge depth and welding distance on surface appearance,macrostructure and mechanical properties of the FSLWed plates were experimentally investigated.The tensile shear load of the FSLWed plates was compared with that of the adhesive-bonded plates.Defect-free FSLWed zones were successfully obtained in all the tool plunge depths and the welding distances.The FSLWed zones exhibited the relatively smooth surface morphologies.Under all the FSLWed conditions,the FSLWed zone exhibited higher average hardness than the base metal.In addition,the upper plate exhibited a higher average hardness than the lower plate,although there was no special tendency in spite of the change in the tool plunge depth and the welding distance.The maximum tensile shear load of the FSLWed plates was much higher than that of the adhesive-bonded aluminum alloy plate.Especially,under the FSLW condition of the plunge depth of 1.8 mm and the welding distance of 40 mm,the tensile shear load of the FSLWed plate reached a level about 41% greater than that of the adhesive-bonded aluminum alloy plate.In addition,the maximum tensile shear load of the FSLWed plate was increased with the increase of the welding distance.

关键词： friction stir lap welding AA5450-O aluminum alloy tool plunge depth welding distance mechanical properties

welding nanofiber and microsphere with carbon dioxide

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Journal of Beijing Institute of Technology 2013年第1期22卷 126-129页

作者：王冬王向轲高鸿邢焰 School of Materials Science and Engineering University of Science and Technology Beijing China Academy of Space Technology

Two types of micro/nano structures, microsphere and nanofibre, were prepared by elec- tro spinning technique and spray drying technique, with the soluble fluorinated poly （ ether ether ke- tone）（3F-PEEK） as the matrix. The micro/nano structures were exhibited in the scanning electron microscope （SEM） micrograghs, and the separated nanofibre and microsphere were observed. The sizes of micro/nano structures were measured by the statistical analysis method. We designed exper- iments to connect up all the micro/nano structures to form new three dimensional micro/nano struc- tures that were observed by SEM. In the experiments, supercritical carbon dioxide （ C02 ） was se- lected as the welding solvent. A series of nanofibers were welded to form three dimensional netlike structures, and the particles were welded to form a porous film. The welding processes were studied by varying the exposure temperature, and the welding mechanism was discussed.

关键词： nanofibre three dimensional netlike supercritical carbon dioxide welding