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Effect of High Magnetic Field on Growth Behavior of compound Layers during Reactive Diffusion between Solid cu and Liquid Al

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journal of Materials Science & Technology 2011年第9期27卷 856-860页

作者： B. Xu W.P. Tong c.Z. Liu H. zhang L. Zuo j.c. he Key Laboratory of National Education Ministry for Electromagnetic Processing of Materials Northeastern University Shenyang 110004 China Department of Materials Engineering Shenyang Institute of Aeronautical Engineering Shenyang 110034 China

The effect of magnetic field on the growth behavior of compound layer was examined at the interface between the solid cu and liquid AI during reactive diffusion. It was found that the thickness of compound layer was reduced by the high magnetic field. The growth activation energy in β, γ1 and ε2 layers under a high magnetic field was larger than those in non magnetic circumstances, the increment percentage being 4.8%, 13.3% and 5.5%, respectively.

关键词： Diffusion Activation energy High magnetic field Al cu

MOTIONS OF ALLOYING ADDITIONS IN GAS STIRRED LADLES

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Acta Metallurgica Sinica(English Letters) 2001年第5期14卷 359-367页

作者： S.c. Fan, B.K. Li and j.c. he Department of Thermal Engineering, Northeastern University, Shenyang 110004, china Dept. of Thermal Eng. Northeastern Univ. Shenyang 110004 China

A mathematical model has been developed to analyze the flow patterns and subsurface traj.c.ories of spherical shaped particles (alloy additions) in gas stirring ladles. First, a numerical method to solve fluid flow problems in conjunction with a curvilinear coordinate system is proposed. The internal boundary in flow field, which must be designated in the cylindrical polar coordinate system, can be avoided by using body- fitted coordinate system (BFc). consequently, computed flow of molten steel and paths of alloying additions are able to cross smoothly the geometric centerline of cylindrical vessel. Second, motion of particles is calculated in the three-dimensional coordinate system, the modification of parameters, such as the drag coefficient and density in the gas plume region, is examined. When the density of sphere is closer and closer to that of fluid, the path of motion is longer and longer. If the plug is moved off-centered to the half of radius, the path of sphere is prolonged, and the sphere may go through the geometric centerline of vessel, reach the deeper region. The immersed depths increase with increasing entry velocities.

关键词： alloying addition gas stirring ladle motion

MATheMATIcAL AND PHYSIcAL MODELING OF INTERFAcIALPheNOMENA IN cONTINOUS cASTING MOULD WITH ARGONINj.c.ION THROUGH SUBMERGED ENTRV NOZZLE

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Acta Metallurgica Sinica(English Letters) 2000年第5期13卷 1079-1086页

作者： H. Lei, M. Y. Zhu and j.c. he (School of Materials and Metallurgy, Northeastern University, Shenyang 110006, china) Sch. of mat. and Metall. Northeastern Univ. Shenyang 110006 China

The study on the fluid flow, meniscus oscillation, slag entrapment in continuous casting mould was conducted mathematically and experimentally. The results show that the inj.c.ion of argon into submerged nozzle enhances the meniscus oscillation, thus increases the probability of slag entrapment, and the critical argon blowing flow rate, which will give rise to slag entrapment, is around 10l/min. The traj.c.ory of bubble is affected by the bubble diameter and the molten steel flow, and the bubble diameter is dominant. The bubble with diameter 1.4mm floats fastest with 0.47m/s terminal velocity.

关键词： continuous casting mould argon inj.c.ion meniscus oscillation slag entrapment mathematical and physical model

ULTRASONIc SEPARATION OF MIcRO-SIZED INcLUSIONS IN MOLTEN METAL

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Acta Metallurgica Sinica(English Letters) 2001年第5期14卷 375-379页

作者： X.Q. Bai and j.c. he Key Laboratory of National Education Ministry for Electromagnetic Processing of Materials, Northeastern University, Shenyang 110004, china Key Laboratory of National Education Ministry for Electromagnetic Processing of Materials Northeastern University

The coagulation time and position of micro-sized non-metallic inclusions in molten metal during ultrasonic separation process were investigated, and the motion course of micro-sized non-metallic inclusions in an ultrasonic standing wave field was numerically simulated. The results of theoretical analysis and numerical simulation show that the movement of inclusions depends on the balance between the acoustic radiation force, effective buoyancy force and viscous drag force. It is presented that micro-sized inclusions, agglomerated at antinode-planes may be removed further with horizon tal ultrasound.``

关键词： ultrasound molten metal micro-sized non-metallic inclusion numerical simulation process parameter

THREE-DIMENSIONAL cHARAcTERISTIcS AND HOMOGENIZATION OF ELEcTROMAGNETIc FIELD IN SOFT-cONTAcT cONTINUOUS cASTING MOLD

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Acta Metallurgica Sinica(English Letters) 2001年第2期14卷 137-142页

作者： A. Y. Deng, G.L. jia and j.c. he (Key Laboratory for Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110004, china) Northeast Univ. Shengyang 110004 China

The three-dimensional electromagnetic characteristics and non-uniform distribution of electromagnetic field in soft-contact continuous casting mold have been analyzed by numerical simulation. The results show that the maximum electromagnetic flux density is found in front of slit; the electromagnetic flux density becomes large as the coil current and slit number increase. In a certain frequency range, the electromagnetic flux density increases with the increase of frequency and the frequency range is different with the change of azimuthal position along the inner wall of mold. The uniformity of electromagnetic field is influenced mainly by frequency and mold structure parameters. Increasing slit number and adjusting slit arrangement position can improve the electromagnetic flux density and the uniformity of electromagnetic field. For a soft-contact mold with 16 slits, when frequency is 20 kHz, the optimal slit arrangement parameter is a:b=1:2, c=0.

关键词： computer simulation Electromagnetic fields Magnetic properties Molds Optimization Three dimensional

EFFEcTS OF LINEAR ELEcTROMAGNETIc STIRRING ON The SOLIDIFIcATION STRUcTURE OF BILLET

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Acta Metallurgica Sinica(English Letters) 2001年第3期14卷 227-234页

作者： H.L. Zhang, E.G. Wang, G.L. jia and j.c. he (Key Laboratory of National Education Ministry for Electromagnetic Processing of Materials, Northeastern University, Shenyang 110004, china) Northeastern Univ. Shenyang 110004 China

The effects of linear electromagnetic stirring (EMS) on the solidification structure of billet were investigated by experiments, and the electromagnetic field and the flow field during the stirring process were analyzed by numerical simulation. The results show that the billet of almost 100% equiaxed grains can be obtained by applying linear EMS at the maximum intensity of 1414 A·Hz1/2, while the maximum electromagnetic force and the maximum velocity in the molten steel are 6386 N·m-3 and 0.22 m·s-1 respectively. It is shown that in the pulsating electromagnetic force which is perpendicular to the movement of the molten steel is an important factor of increasing the equiaxed zone ration in the solidification structure, which further prevents the appearance of white band and internal defects.

关键词： computer simulation Grain growth Magnetoelectric effects Mixing Solidification

A NEW TREATMENT FOR INTERFAcE OF METAL AND DIELEcTRIc IN FDTD METHOD

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Acta Metallurgica Sinica(English Letters) 2001年第1期14卷 42-46页

作者： Z.D. Qian, B. W. Li, E.G. Wang, G.L. jia and j.c. he (Key laboratory of National Education Ministry for Electromagnetic Processing of Materials, Northeastern University, Shenyang 110006, china) Key laboratory of National Education Ministry for Electromagnetic Processing of Materials NortheasternUniversity Shenyang 110006 China

A new treatment for interface of metal and dielectric in finite-difference time domain (FDTD) method was presented, further how and why this treatment should be as it is was explained. The FDTD method was developed to compute the low-frequency electromagnetic fields in the metal instead of the traditional high-frequency ones as it was originally proposed. The computational results agreed well with the experimental ones.

关键词： method treatment for interface electromagnetic field numerical simulation

MAfheMAfIcAL MODEL FOR MELTING PROcESSES OF SOLID ARTIcLES IMMERSED IN METAL BATHS

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Acta Metallurgica Sinica(English Letters) 1999年第3期12卷 259-266页

作者： B.K. Li X.F. Ma X.R. Zhang and j.c. he (Northeastern University, Shenyang 110006, china)(Northeastern University, Shenyang 110006, china)(Northeastern University, Shenyang 110006, china)(Northeastern University, Shenyang 110006, china)

A mathematical model for melting processes of solid particles immersed in metal baths has been develOPed, which includes the cases with the melting point of solid particles greater than, equal to, and lower than freezing point of the bath. Experiments are performed on the melting of ice spheres in water at different temperature. The model is validated by experimental data for melting of ice spheres submerged in water and aluminum spheres immersed in aluminum melt. Finally, the parometers affecting particles melting time such as particle size, bath temperature, and slip velocity are analyzed.

关键词： mathematical model phase change solid particle

Electro-osmotic flow and heat transfer of a non-Newtonian fluid in a hydrophobic microchannel with Navier slip

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journal of Hydrodynamics 2015年第5期27卷 647-657页

作者： MISRA j.c. SINHA A. Adjunct Professor Centre for Healthcare Science and Technology Indian Institute of Engineering Science and Technology School of Medical Science and Technology Indian Institute of Technology

In this paper, we investigate the implications of electro-osmosis on electrohydrodynamic transport of a non-Newtonian fluid on a hydrophobic micro-channel by developing a suitable analytical method. Velocity-slip and temperature-jump conditions are paid due attention. An attempt has been made to examine the effects of rheological and electro-osmotic parameters on the kinematics of the fluid. The nonlinear Poisson-Boltzmann equation governing the formation of the electrical double layer and the body force that is generated by the applied potential are accounted for in the study. Perturbation solutions are presented. In order to exhibit the applicability of the analysis, the problem of electro-osmotic flow and heat transfer of blood in an arteriole has been taken up as an illustrative example of a real-life problem. An intensive quantitative study has been made through numerical computation of the physical variables involved in the analysis, which are of special interest in the study. The computational results are presented graphically. The study reveals that the temperature of blood can be controlled by increasing/decreasing the joule heating parameter.

关键词： electro-osmotic flow hydrophobic microchannel electrical double layer viscoelastic fluid velocity-slip temperature-jump